User terminal and radio communication method

ABSTRACT

In future radio communication systems, an uplink control channel will be transmitted properly. A user terminal has a receiving section that receives frequency hopping information, which indicates whether frequency hopping for an uplink control channel is enabled or not, and a control section that applies at least one of a spreading factor for a time-domain orthogonal cover code, a configuration of a demodulation reference code and a base sequence, to the uplink control channel, based on the frequency hopping information.

TECHNICAL FIELD

The present invention relates to a user terminal and a radiocommunication method in next-generation mobile communication systems.

BACKGROUND ART

In the UMTS (Universal Mobile Telecommunications System) network, thespecifications of long-term evolution (LTE) have been drafted for thepurpose of further increasing high speed data rates, providing lowerlatency and so on (see non-patent literature 1). In addition, for thepurpose of achieving further broadbandization and increased speed beyondLTE, successor systems of LTE (referred to as, for example, “LTE-A(LTE-Advanced),” “FRA (Future Radio Access),” “4G,” “5G,” “5G+(plus),”“NR (New RAT),” “LTE Rel. 14,” “LTE Rel. 15 (or later versions),” and soon) are also under study.

In existing LTE systems (for example, LTE Rel. 8 to 13), downlink (DL)and/or uplink (UL) communication are performed using 1-ms subframes(also referred to as “transmission time intervals (TTIs)” and so on).These subframes each serve as the unit of time for transmitting onechannel-encoded data packet, and serve as the unit of processing in, forexample, scheduling, link adaptation, retransmission control (HARQ(Hybrid Automatic Repeat reQuest)) and so on.

Also, in existing LTE systems (for example, LTE Rel. 8 to 13), a userterminal transmits uplink control information (UCI) by using an uplinkcontrol channel (for example, PUCCH (Physical Uplink Control CHannel))or an uplink data channel (for example, PUSCH (Physical Uplink SharedCHannel)). The format of the uplink control channel is referred to as“PUCCH format (PF)” or the like.

Furthermore, in existing LTE systems, a user terminal multiplexes andtransmits UL channels and DMRSs (DeModulation Reference Signals) in TTIsof 1 ms. In these 1-ms TTIs, multiple DMRSs of different layers of thesame user terminal (or different user terminals) areorthogonal-multiplexed by using cyclic shifts (CSs) and/or orthogonalspreading codes (for example, orthogonal cover codes (OCCs)).

CITATION LIST Non-Patent Literature

Non-Patent Literature 1: 3GPP TS 36.300 V8.12.0 “Evolved UniversalTerrestrial Radio Access (E-UTRA) and Evolved Universal TerrestrialRadio Access Network (E-UTRAN); Overall Description; Stage 2 (Release8),” April, 2010

SUMMARY OF INVENTION Technical Problem

Envisaging future radio communication systems (for example, LTE Rel. 15and later versions, 5G, 5G+, NR, etc.), studies are underway to selectresources (for example, PUCCH resources) for an uplink control channel(for example, PUCCH), based on higher layer signaling and a given fieldvalue in downlink control information (DCI), when UCI is transmittedusing the uplink control channel. In addition, studies are underway tohave PUCCH resources include a number of parameters.

Unless a user terminal properly interprets the parameters included inPUCCH resources that are selected, it may not be possible to transmitthe PUCCH properly.

The present invention has been made in view of the above, and it istherefore an object of the present invention to provide a user terminaland a radio communication method, whereby an uplink control channel canbe transmitted properly.

Solution to Problem

In accordance with one aspect of the present invention, a user terminalhas a receiving section that receives frequency hopping information,which indicates whether frequency hopping for an uplink control channelis enabled or not, and a control section that applies at least one of aspreading factor for a time-domain orthogonal cover code, aconfiguration of a demodulation reference code and a base sequence, tothe uplink control channel, based on the frequency hopping information.

Advantageous Effects of Invention

According to the present invention, an uplink control channel can betransmitted properly in future radio communication systems.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram to show an example of allocation of PUCCH resources;

FIG. 2 is a diagram to show an example of association between PUCCHlengths and SFs;

FIG. 3 is a diagram to show an example of association between SFs andtime-domain OCCs;

FIGS. 4A and 4B are diagrams to show examples of the method ofdetermining SF according to a first example of the present invention;

FIGS. 5A and 5B are diagrams to show examples of the method ofdetermining DMRS configuration according to a second example of thepresent invention;

FIGS. 6A and 6B are diagrams to show examples of the method ofdetermining a base sequence and SF according to an example 3-1 of thepresent invention;

FIGS. 7A and 7B are diagrams to show examples of the method ofdetermining a base sequence and SF according to an example 3-2 of thepresent invention;

FIGS. 8A and 8B are diagrams to show examples of the method ofdetermining SF according to a fourth example of the present invention;

FIGS. 9A and 9B are diagrams to show examples of the method ofdetermining SF according to a fifth example of the present invention;

FIGS. 10A and 10B are diagrams to show examples of the method ofdetermining DMRS configuration according to a sixth example of thepresent invention;

FIGS. 11A and 11B are diagrams to show examples of the method ofdetermining a base sequence and SF according to an example 7-1 of thepresent invention;

FIGS. 12A and 12B are diagrams to show examples of the method ofdetermining a base sequence and SF according to an example 7-2 of thepresent invention;

FIGS. 13A and 13B are diagrams to show examples of the method ofdetermining SF according to an eighth example of the present invention;

FIGS. 14A and 14B are diagrams to show examples of the method ofdetermining DMRS configuration according to a ninth example of thepresent invention;

FIGS. 15A and 15B are diagrams to show examples of the method ofdetermining a base sequence and SF according to an example 10-1 of thepresent invention;

FIGS. 16A and 16B are diagrams to show examples of the method ofdetermining a base sequence and SF according to an example 10-2 of thepresent invention;

FIG. 17 is a diagram to show an exemplary schematic structure of a radiocommunication system according to the present embodiment;

FIG. 18 is a diagram to show an exemplary overall structure of a radiobase station according to the present embodiment;

FIG. 19 is a diagram to show an exemplary functional structure of aradio base station according to the present embodiment;

FIG. 20 is a diagram to show an exemplary overall structure of a userterminal according to the present embodiment;

FIG. 21 is a diagram to show an exemplary functional structure of a userterminal according to the present embodiment; and

FIG. 22 is a diagram to show an exemplary hardware structure of a radiobase station and a user terminal according to the present embodiment.

DESCRIPTION OF EMBODIMENTS

Envisaging future radio communication systems (for example, LTE Rel. 15and later versions, 5G, NR, etc.), formats for uplink control channels(for example, PUCCH) to use to transmit UCI (also referred to as “PUCCHformats (PFs),” and/or the like) are under study. For example, LTE Rel.15 is under research to support five types of formats, namely PF 0 to PF4. Note that the names of PFs in the following description are simplyexamples, and different names may be used.

For example, PFs 0 and 1 are PFs that are used to transmit UCI of up totwo bits (for example, delivery acknowledgment information (alsoreferred to as “HARQ-ACK (Hybrid Automatic RepeatreQuest-ACKnowledgment),” “ACK or NACK,” etc.)). PF 0 can be allocatedto one or two symbols, and therefore, is also referred to as “shortPUCCH,” “sequence-based short PUCCH” and the like. Meanwhile, PF 1 canbe allocated to four to fourteen symbols, and therefore, is alsoreferred to as “long PUCCH” and the like. In PF 1, a number of userterminals may be code-division-multiplexed (CDM) by time-domainblock-wise spreading, which uses at least one of cyclic shifts (CSs) andorthogonal sequences (for example, OCCs (Orthogonal Cover Codes),time-domain OCCs, etc.) in the same resource block (physical resourceblock (PRB)).

PFs 2 to 4 are the PFs that are used to transmit UCI of more than twobits (for example, channel state information (CSI) (or CSI and anHARQ-ACK and/or a scheduling request (SR))). PF 2 can be allocated toone or two symbols, and therefore is also referred to as “short PUCCH”or the like. Meanwhile, PFs 3 and 4 can be allocated to four to fourteensymbols, and therefore, are also referred to as “long PUCCH” and thelike. In PF 4, UCI for a number of user terminals may becode-division-multiplexed (CDM) by using orthogonal sequences (forexample, OCCs, pre-DFT OCCs, frequency-domain OCCs, etc.), and by usingpre-DFT (frequency-domain) block-wise spreading. In PF 4, UCI for anumber of user terminals may be code-division-multiplexed (CDM) by usingdemodulation reference signals (DMRSs), and by using pre-DFT(frequency-domain) block-wise spreading.

Resources (for example, PUCCH resources) that are used to transmit thisuplink control channel are allocated by using higher layer signalingand/or downlink control information (DCI). Here, higher layer signalingmay refer to, for example, at least one of RRC (Radio Resource Control)signaling, system information (for example, at least one of RMSI(Remaining Minimum System Information), OSI (Other System Information),MIB (Master Information Block) and SIB (System Information Block)), andbroadcast information (PBCH (Physical Broadcast CHannel)).

To be more specific, one or more sets (PUCCH resource sets), eachcomprised of one or more PUCCH resources, are reported to (configuredin) a user terminal via higher layer signaling. For example, K PUCCHresource sets (where, for example, 1≤K≤4) may be reported from a radiobase station to the user terminal. Each PUCCH resource set may becomprised of M PUCCH resources (where, for example, 4≤M≤8).

The user terminal may select a single PUCCH resource set, out of the KPUCCH resource sets that are configured, based on the payload size ofthe UCI (or “UCI payload size”). The UCI payload size may be the numberof UCI bits, not including the cyclic redundancy check (CRC) bits.

The user terminal may select the PUCCH resource to use to transmit theUCI, out of the M PUCCH resources included in the selected PUCCHresource set, based on at least one of DCI and implicit information(also referred to as “implicit indication information,” “implicitindex,” etc.).

FIG. 1 is a diagram to show an example of allocation of PUCCH resources.Referring to FIG. 1, K=4 holds as an example, and four PUCCH resourcesets #0 to #3 are configured from the radio base station to the userterminal via higher layer signaling. Furthermore, PUCCH resource sets #0to #3 each include M PUCCH resources #0 to #M−1 (where, for example,4≤M≤8). Note that these PUCCH resource sets may all include the samenumber of PUCCH resources, or include different numbers of PUCCHresources.

In FIG. 1, each PUCCH resource configured in the user terminal mayinclude at least one of the following parameter values (these parametersmay be also referred to as “fields,” “information,” etc.). Note that,for each parameter, a range of possible values may be defined, per PUCCHformat.

-   -   The symbol where the PUCCH starts being allocated (the starting        symbol, the first symbol, etc.);    -   The number of symbols allocated to the PUCCH in a slot (the        duration allocated to the PUCCH);    -   The index of the resource block where the PUCCH starts being        allocated (the starting PRB, the first (lowest) PRB, etc.) (for        example, PUCCH-starting-PRB);    -   The number of PRBs allocated to the PUCCH (for example, for PF 2        or 3); Whether frequency hopping is enabled or disabled for        PUCCH resources (for example, PUCCH-frequency-hopping);    -   The frequency resource after frequency hopping (second hop) (for        example, the index of the starting PRB or the first (lowest) PRB        in a second hop, PUCCH-2nd-hop-PRB, etc.);    -   The index of the initial cyclic shift (CS) (for example, for PF        0 or 1);    -   The index of an orthogonal sequence in the time domain (for        example, a time-domain OCC) (for example, for PF 1);    -   The length of the orthogonal sequence (for example, pre-DFT OCC)        used in block-wise spreading before the discrete Fourier        transform (DFT) (also referred to as “pre-DFT OCC length,”        “spreading factor,” etc.) (for example, for PF 4); and    -   The index of the orthogonal sequence for use in pre-DFT        block-wise spreading (for example, pre-DFT OCC) (for example,        for PF 4).

As shown in FIG. 1, when PUCCH resource sets #0 to #3 are configured ina user terminal, the user terminal selects one of the PUCCH resource setbased on UCI payload size.

For example, when the UCI payload size is one or two bits, PUCCHresource set #0 is selected. Also, when the UCI payload size is threebits or more and N₂−1 bits or less, PUCCH resource set #1 is selected.Furthermore, when the UCI payload size is N₂ bits or more and N₃−1 bitsor less, PUCCH resource set #2 is selected. Similarly, when the UCIpayload size is N₃ bits or more and N₃−1 bits or less, PUCCH resourceset #3 is selected.

In this way, the range of UCI payload size in which PUCCH resource set#i (i=0, . . . , K−1) is selected is expressed as N_(i) bits or more andN_(i+1)−1 bits or less (that is, {N_(i), . . . , N_(i+1)−1} bits).

Here, the starting locations (the numbers of starting bits) N₀ and N₁for the UCI payload sizes for PUCCH resource sets #0 and #1 may be 1 and3, respectively. By this means, PUCCH resource set #0 is selected whenUCI of up to two bits is transmitted, so that PUCCH resource set #0 mayinclude PUCCH resources #0 to #M−1 for at least one of PF 0 and PF 1. Onthe other hand, one of PUCCH resource sets #1 to #3 is selected when UCIof more than two bits is transmitted, so that PUCCH resource sets #1 to#3 may include PUCCH resources #0 to #M−1 for at least one of PF 2, PF 3and PF 1, respectively.

If i=2, . . . , K−1 holds, information to show the starting location(N₁) of the UCI payload size for PUCCH resource set #i (startinglocation information) may be reported to (configured in) the userterminal by using higher layer signaling. This starting location (N_(i))may be user terminal-specific. For example, the starting location(N_(i)) may be configured to a value in a range of 4 bits to 256 bits(for example, a multiple of four). For example, referring to FIG. 1,information to show the starting locations (N₂ and N₃) of the UCIpayload sizes for PUCCH resource sets #2 and #3 are reported to the userterminal via higher layer signaling (for example, user-specific RRCsignaling), respectively.

The maximum UCI payload size for each PUCCH resource set is given byN_(K−1). N_(K) may be explicitly reported to (configured in) the userterminal by higher layer signaling and/or DCI, or may be derivedimplicitly. For example, in FIG. 1, N₀=1 and N₁=3 may be specified inthe specification, and N₂ and N₃ may be reported via higher layersignaling. Also, N₄ may be specified in the specification (for example,N₄=1000).

In the case shown in FIG. 1, the user terminal can select a single PUCCHresource to use to transmit UCI, out of PUCCH resources #0 to #M−1included in the PUCCH resource set selected based on the UCI payloadsize, based on the value of a given field in DCI and/or otherparameters. For example, when the number of bits in this given field istwo, four types of PUCCH resources can be specified. Other parametersmay be a CCE index. For example, a PUCCH resource may be associated witha combination of a two-bit DCI and another parameter, or may beassociated with a three-bit DCI.

For example, where there are a number of PUCCH resource sets configuredby higher layer, if UCI is an HARQ-ACK, the user terminal (userequipment (UE)) may select one PUCCH resource set, out of a number ofPUCCH resource sets configured by higher layer, based on the UCI payloadsize, and select one PUCCH resource from the selected PUCCH resource setbased on DCI and/or another parameter. The above-described method ofreporting a PUCCH resource by using a PUCCH resource set may be alsoused when UCI is encoded with an HARQ-ACK and another UCI (for example,CSI and/or an SR) and transmitted simultaneously.

On the other hand, when UCI includes no HARQ-ACK, PUCCH resources may bereported without using PUCCH resource sets. For example, if UCI is CSIand/or an SR, the UE may use PUCCH resources that are configuredsemi-statically by higher layer.

Also, the number of slots for transmitting the PUCCH (the number ofPUCCH slots, the number of PUCCH repetitions, etc.), or N_(PUCCH)^(repeat), may be configured in the UE by means of a higher layerparameter (for example, PUCCH-F1-number-of-slots for PF 1,PUCCH-F3-number-of-slots for PF 3, or PUCCH-F4-number-of-slots for PF4). If N_(PUCCH) ^(repeat) is greater than one, the UE transmits thePUCCH over multiple slots (N_(PUCCH) ^(repeat) slots).

The UE repeats the UCI in the PUCCH transmission of the first slot ofN_(repeat) slots, in the PUCCH transmission in each of the rest of theN_(repeat)−1 slots.

Furthermore, in PF 1, the number of user terminals to be multiplexedusing time-domain OCCs is determined based on the duration of PUCCH(long-PUCCH duration, the number of symbols, etc.). The maximum numberof user terminals to be multiplexed using time-domain OCCs may beparaphrased as “OCC multiplexing capacity,” “OCC length,” “spreadingfactor (SF)” and so on.

When UEs are multiplexed using cyclic shifts (CSs) in addition totime-domain OCCs, the maximum value of multiplexing capacity in a givenresource is the maximum value of the OCC multiplexing capacity×thenumber of CSs. The number of CSs may be a given value (for example, 12).

When time-domain OCCs are applied to a PUCCH (for example, PF 1), fromthe perspective of maintaining orthogonality, the same base sequenceneeds to be used (the same base sequence needs to be applied) within aperiod where one time-domain OCC is multiplied. Note that differentvalues may be applied to the cyclic shifts to apply to the base sequencewithin the period where one time-domain OCC is multiplied.

As shown in FIG. 2, the SFs of time-domain OCCs for PUCCH format 1 maybe associated with PUCCH lengths (the numbers of PUCCH symbols). SFswithout intra-slot hopping (with no intra-slot hopping) and SFs withintra-slot hopping may be associated with PUCCH lengths. When intra-slothopping is carried out once, SFs with intra-slot hopping may include anSF for the first hop (1st hop, before frequency hopping, and hoppingindex m=0) and an SF for the second hop (2nd hop, after frequencyhopping, and hopping index m=1). In this way, a table to show the SFsfor each value of PUCCH length may be defined in the specification.

As shown in FIG. 3, SFs may be associated with as many time-domain OCCsas the SFs. Here, the time-domain OCC is represented by exp(j2πφ/SF),and FIG. 3 shows φ, which determines the time-domain OCC. In this way, atable to show at least one time-domain OCC for each value of SF may bedefined in the specification.

The association between PUCCH lengths and SFs and the associationbetween SFs and time-domain OCCs may be configured in advance, or may bedefined in the specification.

As for the parameters included in PUCCH resources, for frequencyhopping, whether frequency hopping of PUCCH resources is enabled ordisabled may be indicated by a higher layer parameter (for example,PUCCH-frequency-hopping). The index of the first PRB (the lowest PRB)before frequency hopping or when frequency hopping is not used may beindicated by a higher layer parameter (for example, PUCCH-starting-PRB).The index of the first PRB (the lowest PRB) after frequency hopping maybe indicated by PUCCH-2nd-hop-PRB, for example.

However, the details of UE operations in accordance with theconfiguration of frequency hopping have not been determined yet. Forexample, it is not clear how the UE operates based on parameters relatedto frequency hopping, such as PUCCH-frequency-hopping. So, the presentinventors have worked on UE operations in accordance with theconfiguration of PUCCH frequency hopping, and arrived at the presentinvention.

Now, embodiments of the present invention will be described below indetail. The embodiments described below may be each used alone, or maybe used in combinations.

First Example

With a first example of the present invention, a method, by which UEdetermines the SF for PUCCH format 1 when the UE is configured withPUCCH-starting-PRB, PUCCH-2nd-hop-PRB and PUCCH-frequency-hopping (orthree parameters equivalent to these) and PUCCH-starting-PRB andPUCCH-2nd-hop-PRB are mutually equal, will be described below.

SFs for PUCCH format 1 are associated with PUCCH lengths, SFs withoutintra-slot hopping and SFs with intra-slot hopping are associated withPUCCH lengths, and SFs with intra-slot hopping include first-hop SFs andsecond-hop SFs (see, for example, FIG. 2). Also, time-domain OCCsequences are associated with SFs (see, for example, FIG. 3).

Note that the UE may use SFs with intra-slot hopping even if the UE doesnot actually perform intra-slot frequency hopping for PUCCH.

The UE may determine the SF based on PUCCH-starting-PRB,PUCCH-2nd-hop-PRB, and PUCCH-frequency-hopping, among the PUCCHresources that are configured.

If PUCCH-starting-PRB is equal to PUCCH-2nd-hop-PRB andPUCCH-frequency-hopping is disabled, as shown in FIG. 4A, the UE may usean SF without intra-slot hopping.

An SF without intra-slot hopping is greater than an SF with intra-slothopping (each of the first-hop SF and the second-hop SF). By using SFswithout intra-slot hopping, the OCC length becomes longer (the number ofOCCs becomes larger) than when using SFs with intra-slot hopping.Consequently, the OCC multiplexing capacity (the maximum number of UEsto multiplex) can be increased.

If PUCCH-starting-PRB is equal to PUCCH-2nd-hop-PRB andPUCCH-frequency-hopping is enabled, as shown in FIG. 4B, the UE may useSFs with intra-slot hopping. In this case, the UE may use the first-hopSF before the frequency hopping timing, and use the second-hop SF afterthe frequency hopping timing. Here, the above frequency hopping timingmay be the same as the frequency hopping timing for whenPUCCH-starting-PRB is different from PUCCH-2nd-hop-PRB andPUCCH-frequency-hopping is enabled. For example, the number of symbolsof the first hop (the period before the frequency hopping timing in theslot) may be floor(the number of PUCCH symbols/2), and the number ofsymbols of the second hop (the period after the frequency hopping timingin the slot) may be ceil(the number of PUCCH symbols/2).

An SF with intra-slot hopping (each of the first-hop SF and thesecond-hop SF) is smaller than an SF without intra-slot hopping. Byusing SFs with intra-slot hopping, the OCC length becomes shorter thanwhen using an SF without intra-slot hopping. Consequently, when the UEmoves at high speed, the signal in a time-domain OCC varies less, andthe orthogonality of the time-domain OCC is less likely to deteriorate,so that the robustness against high-speed movement of the UE increases.

According to the first example, the NW (network, including, for example,a radio base station, a gNB, etc.) can flexibly change the SF (the OCClength or the OCC multiplexing capacity) based on the configuration offrequency hopping.

Second Example

With a second example of the present invention, a method, by which UEdetermines the DMRS configuration for PUCCH format 3 and/or 4 when theUE is configured with PUCCH-starting-PRB, PUCCH-2nd-hop-PRB andPUCCH-frequency-hopping (or three parameters equivalent to these) andPUCCH-starting-PRB and PUCCH-2nd-hop-PRB are mutually equal, will bedescribed below. The DMRS configuration may be the locations (forexample, the symbols) of the DMRS.

Similar to the case of SFs, for the DMRS configurations for PUCCH format3 and/or 4, DMRS configurations without intra-slot hopping (that is,with no intra-slot hopping) and DMRS configurations with intra-slothopping may be defined in the specification. A DMRS configuration withintra-slot hopping may include a DMRS configuration for the first hopand a DMRS configuration for the second hop.

The UE may determine the DMRS configuration based on PUCCH-starting-PRB,PUCCH-2nd-hop-PRB, and PUCCH-frequency-hopping, among the PUCCHresources configured.

If PUCCH-starting-PRB is equal to PUCCH-2nd-hop-PRB, andPUCCH-frequency-hopping is disabled, as shown in FIG. 5A, the UE may usea DMRS configuration without intra-slot hopping.

If PUCCH-starting-PRB is equal to PUCCH-2nd-hop-PRB, andPUCCH-frequency-hopping is enabled, as shown in FIG. 5B, the UE may usea DMRS configuration with intra-slot hopping. In this case, the UE mayuse the first-hop DMRS configuration before the frequency hoppingtiming, and use the second-hop DMRS configuration after the frequencyhopping timing. Here, the above frequency hopping timing may be the sameas the frequency hopping timing for when PUCCH-starting-PRB is differentfrom PUCCH-2nd-hop-PRB and PUCCH-frequency-hopping is enabled. Forexample, the number of symbols of the first hop (the period before thefrequency hopping timing in the slot) may be floor(the number of PUCCHsymbols/2), and the number of symbols of the second hop (the periodafter the frequency hopping timing in the slot) may be ceil(the numberof PUCCH symbols/2).

Note that the locations of the DMRS where frequency hopping is notapplied may be the same as the locations of the DMRS where frequencyhopping is applied.

According to the second example, the NW can flexibly change the DMRSconfiguration based on the configuration of frequency hopping.

Third Example

With a third example of the present invention, a method, by which UEdetermines the base sequence for at least one of PUCCH formats 0 to 4(in particular, PUCCH formats 0, 1, 3 and 4) and/or the SF for PUCCHformat 1 when the UE is configured with PUCCH-starting-PRB,PUCCH-2nd-hop-PRB and PUCCH-frequency-hopping (or three parametersequivalent to these) and PUCCH-starting-PRB and PUCCH-2nd-hop-PRB aremutually equal, will be described below. The base sequence may berepresented by a base sequence index.

The base sequence may be a CAZAC (Constant Amplitude ZeroAuto-Correlation) sequence such as a Zadoff-Chu sequence (for example, alow-PAPR (Peak-to-Average Power Ratio) sequence), may be a sequencedefined in the specification (for example, a low-PAPR sequence), or maybe a pseudo spreading sequence (for example, a Gold sequence). Forexample, a PUCCH having a bandwidth of one PRB may use one of a givennumber of sequences (where the given number may be, for example, 30, 60or a given value determined from the length of the base sequence)defined in the specification, as a base sequence. The base sequence maybe used for UCI, or may be used for the DMRS.

Similar to the first example, for SFs for PUCCH format 1, SFs withoutintra-slot hopping and SFs with intra-slot hopping may be configured inadvance, or may be defined in the specification.

The UE may determine the base sequence and/or the SF based onPUCCH-starting-PRB, PUCCH-2nd-hop-PRB and PUCCH-frequency-hopping, amongthe PUCCH resources configured.

As base sequence hopping, a method of hopping the base sequence per slot(on a slot level) and a method of hopping the base sequence at thetiming of frequency hopping (per OCC length) (on a frequency-hop level,a time-domain-OCC level, etc.) may be possible.

Example 3-1

A case will be described, with example 3-1, in which base sequencehopping on a slot level is applied.

If PUCCH-starting-PRB is equal to PUCCH-2nd-hop-PRB, andPUCCH-frequency-hopping is disabled, as shown in FIG. 6A, the UE may usean SF without intra-slot hopping.

An SF without intra-slot hopping is greater than an SF with intra-slothopping (each of the first-hop SF and the second-hop SF). By using SFswithout intra-slot hopping, the OCC length becomes longer (the number ofOCCs becomes larger) than when using SFs with intra-slot hopping.Consequently, the OCC multiplexing capacity (the maximum number of UEsto multiplex) can be increased.

Also, regardless of whether PUCCH-frequency-hopping is enabled ordisabled, the UE uses one base sequence #m₀ in one slot. In other words,the base sequence does not change before and after the frequency hoppingtiming.

If PUCCH-starting-PRB is equal to PUCCH-2nd-hop-PRB, andPUCCH-frequency-hopping is enabled, as shown in FIG. 6B, the UE may useSFs with intra-slot hopping. In this case, the UE may use the first-hopSF before the frequency hopping timing, and use the second-hop SF afterthe frequency hopping timing. Here, the above frequency hopping timingmay be the same as the frequency hopping timing for whenPUCCH-starting-PRB is different from PUCCH-2nd-hop-PRB andPUCCH-frequency-hopping is enabled. For example, the number of symbolsof the first hop (the period before the frequency hopping timing in theslot) may be floor(the number of PUCCH symbols/2), and the number ofsymbols of the second hop (the period after the frequency hopping timingin the slot) may be ceil(the number of PUCCH symbols/2).

An SF with intra-slot hopping (each of the first-hop SF and thesecond-hop SF) is smaller than an SF without intra-slot hopping. Byusing SFs with intra-slot hopping, the OCC length becomes shorter thanwhen using an SF without intra-slot hopping. Consequently, when the UEmoves at high speed, the signal in a time-domain OCC varies less, andthe orthogonality of the time-domain OCC is less likely to deteriorate,so that the robustness against high-speed movement of the UE increases.

According to an example 3-1, the NW can change the SF (OCC length),flexibly, depending on whether PUCCH-frequency-hopping is enabled ordisabled.

Example 3-2

A case will be described, with an example 3-2, in which base sequencehopping on a frequency-hop level is applied.

Note that even if UE does not actually perform frequency hopping for thePUCCH, the UE may perform base sequence hopping at the timing offrequency hopping.

If PUCCH-starting-PRB is equal to PUCCH-2nd-hop-PRB, andPUCCH-frequency-hopping is disabled, as shown in FIG. 7A, the UE may usean SF without intra-slot hopping.

An SF without intra-slot hopping is greater than an SF with intra-slothopping (each of the first-hop SF and the second-hop SF). By using SFswithout intra-slot hopping, the OCC length becomes longer (the number ofOCCs becomes larger) than when using SFs with intra-slot hopping.Consequently, the OCC multiplexing capacity (the maximum number of UEsto multiplex) can be increased.

Also, the UE does not perform frequency hopping whenPUCCH-frequency-hopping is disabled, and it naturally follows that theUE does not perform base sequence hopping on a frequency-hop leveleither. Consequently, the UE uses one base sequence #m₀ in one slot.

If PUCCH-starting-PRB is equal to PUCCH-2nd-hop-PRB, andPUCCH-frequency-hopping is enabled, as shown in FIG. 7B, the UE may useSFs with intra-slot hopping. In this case, the UE may use the first-hopSF before the frequency hopping timing, and use the second-hop SF afterthe frequency hopping timing.

An SF with intra-slot hopping (each of the first-hop SF and thesecond-hop SF) is smaller than an SF without intra-slot hopping. Byusing SFs with intra-slot hopping, the OCC length becomes shorter thanwhen using an SF without intra-slot hopping. Consequently, when the UEmoves at high speed, the signal in a time-domain OCC varies less, andthe orthogonality of the time-domain OCC is less likely to deteriorate,so that the robustness against high-speed movement of the UE increases.

Also, if PUCCH-frequency-hopping is enabled, the UE performs basesequence hopping (switches the base sequence), at the timing offrequency hopping, for at least one of PUCCH formats 0 to 4. In thiscase, the UE may use base sequence #m₀ before the frequency hoppingtiming, and use base sequence #m₁ after the frequency hopping timing.

By changing the base sequence within a slot, a number of UEs are morelikely to use different base sequences, for example, at least eitherbefore or after frequency hopping (base sequence hopping). Therefore,the possibility that base sequences collide with each other decreases,and the robustness to inter-cell interference increases.

According to the third example, the NW can change the SF, flexibly,based on the configuration of frequency hopping. Also, the UE canproperly control base sequence hopping based on the configuration offrequency hopping.

Also, since it is preferable to use the same base sequence within onetime-domain OCC, base sequence hopping on a slot level or afrequency-hop level is applied. Meanwhile, changing the cyclic shiftwithin one time-domain OCC has no impact on the orthogonality oftime-domain OCCs, so that hopping in units of symbols (or on a symbollevel) may be applied to the cyclic shift, or hopping on a slot level orcyclic shift hopping on a frequency-hop level may be applied, as withbase sequences.

Fourth Example

With a fourth example of the present invention, a method of reducing thehigher layer parameters related to frequency hopping, for at least oneof PUCCH formats 0 to 4, will be described.

UE may determine whether frequency hopping for the PUCCH is enabled ornot, based on PUCCH-starting-PRB and PUCCH-2nd-hop-PRB, among the PUCCHresources configured. In other words, PUCCH-frequency-hopping needs notbe reported to the UE.

When the UE is configured with PUCCH-starting-PRB and PUCCH-2nd-hop-PRBthat are mutually equal, as shown in FIG. 8A, the UE may assume thatPUCCH-frequency-hopping is disabled.

For example, the UE may determine at least one of the SF, the DMRSconfiguration and the base sequence when PUCCH-frequency-hopping isdisabled, in accordance with at least one of the first example, thesecond example and the third example.

When the UE is configured with PUCCH-starting-PRB and PUCCH-2nd-hop-PRBthat are mutually different, as shown in FIG. 8B, the UE may assume thatPUCCH-frequency-hopping is enabled.

For example, the UE may determine at least one of the SF, the DMRSconfiguration and the base sequence when PUCCH-frequency-hopping isenabled, in accordance with at least one of the first example, thesecond example, and the third example.

According to the fourth example, the NW does not report the higher layerparameter (for example, PUCCH-frequency-hopping) that indicates whetherPUCCH frequency hopping is enabled or disabled, to the UE, so that it ispossible to reduce the higher layer parameters and simplify the UEoperations.

Fifth Example

With a fifth example of the present invention, a method, by which UEdetermines the SF (OCC length) for PUCCH format 1 based onPUCCH-starting-PRB and PUCCH-2nd-hop-PRB, when the UE is configured atleast with PUCCH-starting-PRB and PUCCH-2nd-hop-PRB (or two parametersequivalent to these), will be described.

When the UE is configured with PUCCH-starting-PRB and PUCCH-2nd-hop-PRBthat are mutually equal, as shown in FIG. 9A, the UE may use an SFwithout intra-slot hopping, regardless of whetherPUCCH-frequency-hopping is enabled or disabled.

An SF without intra-slot hopping is greater than an SF with intra-slothopping (each of the first-hop SF and the second-hop SF). By using SFswithout intra-slot hopping, the OCC length becomes longer (the number ofOCCs becomes larger) than when using SFs with intra-slot hopping.Consequently, the OCC multiplexing capacity (the maximum number of UEsto multiplex) can be increased.

When the UE is configured with PUCCH-starting-PRB and PUCCH-2nd-hop-PRBthat are mutually different, as shown in FIG. 9B, the UE may use SFswith intra-slot hopping. In this case, the UE may use the first-hop SFbefore the frequency hopping timing, and use the second-hop SF after thefrequency hopping timing. Here, as for the timing for frequency hopping,which has been described above, the number of symbols of the first hop(the period before the frequency hopping timing in the slot) may befloor(the number of PUCCH symbols/2), and the number of symbols of thesecond hop (the period after the frequency hopping timing in the slot)may be ceil(the number of PUCCH symbols/2).

An SF with intra-slot hopping (each of the first-hop SF and thesecond-hop SF) is smaller than an SF without intra-slot hopping. Byusing SFs with intra-slot hopping, the OCC length becomes shorter thanwhen using an SF without intra-slot hopping. Consequently, when the UEmoves at high speed, the signal in a time-domain OCC varies less, andthe orthogonality of the time-domain OCC is less likely to deteriorate,so that the robustness against high-speed movement of the UE increases.

The UE performs frequency hopping for the PUCCH in the slot, so that afrequency diversity gain can be achieved.

When the UE is configured with PUCCH-starting-PRB and PUCCH-2nd-hop-PRBthat are mutually different, the UE may assume thatPUCCH-frequency-hopping is not configured disabled (that is, configuredenabled). Also, when the UE is configured with PUCCH-starting-PRB andPUCCH-2nd-hop-PRB that are mutually different, the UE may use SFs withintra-slot hopping, regardless of whether PUCCH-frequency-hopping isenabled or disabled.

The UE may carry out UE operations so that the UE uses an SF withoutintra-slot hopping when PUCCH-frequency-hopping is configured disabledand PUCCH-starting-PRB and PUCCH-2nd-hop-PRB that are mutually equal areconfigured, and the UE uses SFs with intra-slot hopping whenPUCCH-frequency-hopping is configured enabled and PUCCH-starting-PRB andPUCCH-2nd-hop-PRB that are mutually different are configured. WhenPUCCH-frequency-hopping is configured disabled and PUCCH-starting-PRBand PUCCH-2nd-hop-PRB that are mutually different are configured, the UEto carry out the above UE operations may assume that this configurationis not valid (the UE may assume that this combination is not to beconfigured). When PUCCH-frequency-hopping is configured enabled andPUCCH-starting-PRB and PUCCH-2nd-hop-PRB that are mutually equal areconfigured, the UE to carry out the above UE operations may assume thatthis configuration is not valid (the UE may assume that this combinationis not to be configured).

According to the fifth example, the NW can change the SF, flexibly,based on the configuration of frequency hopping.

The NW needs not report the higher layer parameter to indicate whetherfrequency hopping for the PUCCH is enabled or disabled (for example,PUCCH-frequency-hopping), to the UE. In this case, it is possible toreduce the higher layer parameters, and simplify the UE operations.

Sixth Example

With a sixth example of the present invention, a method, by which UEdetermines the DMRS configurations for PUCCH format 3 and/or 4 based onPUCCH-starting-PRB and PUCCH-2nd-hop-PRB, when the UE is configured atleast with PUCCH-starting-PRB and PUCCH-2nd-hop-PRB (or two parametersequivalent to these), will be described.

Similar to the case of SFs, for the DMRS configurations for PUCCH format3 and/or 4, DMRS configurations without intra-slot hopping (that is,with no intra-slot hopping) and DMRS configurations with intra-slothopping may be defined in the specification. A DMRS configuration withintra-slot hopping may include a DMRS configuration for the first hopand a DMRS configuration for the second hop.

The UE may determine the DMRS configuration based on PUCCH-starting-PRBand PUCCH-2nd-hop-PRB, among the PUCCH resources configured.

When the UE is configured with PUCCH-starting-PRB and PUCCH-2nd-hop-PRBthat are mutually equal, as shown in FIG. 10A, the UE may use a DMRSconfiguration without intra-slot hopping, regardless of whetherPUCCH-frequency-hopping is enabled or disabled.

When the UE is configured with PUCCH-starting-PRB and PUCCH-2nd-hop-PRBthat are mutually different, as shown in FIG. 10B, the UE may use a DMRSconfiguration with intra-slot hopping. In this case, the UE may use thefirst-hop DMRS configuration before the frequency hopping timing, anduse the second-hop DMRS configuration after the frequency hoppingtiming. Here, as for the timing for frequency hopping, which has beendescribed above, the number of symbols of the first hop (the periodbefore the frequency hopping timing in the slot) may be floor(the numberof PUCCH symbols/2), and the number of symbols of the second hop (theperiod after the frequency hopping timing in the slot) may be ceil(thenumber of PUCCH symbols/2).

When the UE is configured with PUCCH-starting-PRB and PUCCH-2nd-hop-PRBthat are mutually different, the UE may assume thatPUCCH-frequency-hopping is not configured disabled (that is, configuredenabled). Also, when the UE is configured with PUCCH-starting-PRB andPUCCH-2nd-hop-PRB that are mutually different, the UE may use a DMRSconfiguration with intra-slot hopping, regardless of whetherPUCCH-frequency-hopping is enabled or disabled.

The UE may carry out UE operations so that the UE uses a DMRSconfiguration without intra-slot hopping when PUCCH-frequency-hopping isconfigured disabled and PUCCH-starting-PRB and PUCCH-2nd-hop-PRB thatare mutually equal are configured, and the UE uses a DMRS configurationwith intra-slot hopping when PUCCH-frequency-hopping is configuredenabled and PUCCH-starting-PRB and PUCCH-2nd-hop-PRB that are mutuallydifferent are configured. When PUCCH-frequency-hopping is configureddisabled and PUCCH-starting-PRB and PUCCH-2nd-hop-PRB that are mutuallydifferent are configured, the UE to carry out the above UE operationsmay assume that this configuration is not valid (the UE may assume thatthis combination is not to be configured). When PUCCH-frequency-hoppingis configured enabled and PUCCH-starting-PRB and PUCCH-2nd-hop-PRB thatare mutually equal are configured, the UE to carry out the above UEoperations may assume that this configuration is not valid (the UE mayassume that this combination is not to be configured).

Note that the locations of the DMRS where frequency hopping is notapplied may be the same as the locations of the DMRS where frequencyhopping is applied.

According to the sixth example, the NW can flexibly change the DMRSconfiguration based on the configuration of frequency hopping.

The NW needs not to report the higher layer parameter to indicatewhether frequency hopping for the PUCCH is enabled or disabled (forexample, PUCCH-frequency-hopping), to the UE. In this case, it ispossible to reduce the higher layer parameters, and simplify the UEoperations.

Seventh Example

With a seventh example of the present invention, a method, by which UEdetermines the base sequence for at least one of PUCCH formats 0 to 4(in particular, PUCCH formats 0, 1, 3, and 4) and/or the SF for PUCCHformat 1, based on PUCCH-starting-PRB and PUCCH-2nd-hop-PRB, when the UEis configured at least with PUCCH-starting-PRB and PUCCH-2nd-hop-PRB (ortwo parameters equivalent to these), will be described.

The UE may determine the base sequence and/or the SF based onPUCCH-starting-PRB and PUCCH-2nd-hop-PRB, among the PUCCH resourcesconfigured.

Example 7-1

A case will be described, with example 7-1, in which base sequencehopping on a slot level is applied.

When the UE is configured with PUCCH-starting-PRB and PUCCH-2nd-hop-PRBthat are mutually equal, as shown in FIG. 11A, the UE may use an SFwithout intra-slot hopping, regardless of whetherPUCCH-frequency-hopping is enabled or disabled.

An SF without intra-slot hopping is greater than an SF with intra-slothopping (each of the first-hop SF and the second-hop SF). By using SFswithout intra-slot hopping, the OCC length becomes longer (the number ofOCCs becomes larger) than when using SFs with intra-slot hopping.Consequently, the OCC multiplexing capacity (the maximum number of UEsto multiplex) can be increased.

When the UE is configured with PUCCH-starting-PRB and PUCCH-2nd-hop-PRBthat are mutually different, as shown in FIG. 11B, the UE may use SFswith intra-slot hopping. In this case, the UE may use the first-hop SFbefore the frequency hopping timing, and use the second-hop SF after thefrequency hopping timing. Here, as for the timing for frequency hopping,which has been described above, the number of symbols of the first hop(the period before the frequency hopping timing in the slot) may befloor(the number of PUCCH symbols/2), and the number of symbols of thesecond hop (the period after the frequency hopping timing in the slot)may be ceil(the number of PUCCH symbols/2).

An SF with intra-slot hopping (each of the first-hop SF and thesecond-hop SF) is smaller than an SF without intra-slot hopping. Byusing SFs with intra-slot hopping, the OCC length becomes shorter thanwhen using an SF without intra-slot hopping. Consequently, when the UEmoves at high speed, the signal in a time-domain OCC varies less, andthe orthogonality of the time-domain OCC is less likely to deteriorate,so that the robustness against high-speed movement of the UE increases.

The UE uses one base sequence #m₀ in one slot, regardless of whetherPUCCH-starting-PRB and PUCCH-2nd-hop-PRB are equal or not. In otherwords, the base sequence does not change before and after the frequencyhopping timing.

When the UE is configured with PUCCH-starting-PRB and PUCCH-2nd-hop-PRBthat are mutually different, the UE may assume thatPUCCH-frequency-hopping is not configured disabled (that is, configuredenabled). Also, when the UE is configured with PUCCH-starting-PRB andPUCCH-2nd-hop-PRB that are mutually different, the UE may use SFs withintra-slot hopping, regardless of whether PUCCH-frequency-hopping isenabled or disabled.

The UE may carry out UE operations so that the UE uses an SF withoutintra-slot hopping when PUCCH-frequency-hopping is configured disabledand PUCCH-starting-PRB and PUCCH-2nd-hop-PRB that are mutually equal areconfigured, and the UE uses SFs with intra-slot hopping whenPUCCH-frequency-hopping is configured enabled and PUCCH-starting-PRB andPUCCH-2nd-hop-PRB that are mutually different are configured. WhenPUCCH-frequency-hopping is configured disabled and PUCCH-starting-PRBand PUCCH-2nd-hop-PRB that are mutually different are configured, the UEto carry out the above UE operations may assume that this configurationis not valid (the UE may assume that this combination is not to beconfigured). When PUCCH-frequency-hopping is configured enabled andPUCCH-starting-PRB and PUCCH-2nd-hop-PRB that are mutually equal areconfigured, the UE to carry out the above UE operations may assume thatthis configuration is not valid (the UE may assume that this combinationis not to be configured).

According to an example 7-1, the NW can change the SF (OCC length),flexibly, depending on whether PUCCH-starting-PRB and PUCCH-2nd-hop-PRBare equal or not.

Example 7-2

A case will be described, with an example 7-2, in which base sequencehopping on a frequency-hop level is applied.

When the UE is configured with PUCCH-starting-PRB and PUCCH-2nd-hop-PRBthat are mutually equal, as shown in FIG. 12A, the UE may use an SFwithout intra-slot hopping, regardless of whetherPUCCH-frequency-hopping is enabled or disabled.

An SF without intra-slot hopping is greater than an SF with intra-slothopping (each of the first-hop SF and the second-hop SF). By using SFswithout intra-slot hopping, the OCC length becomes longer (the number ofOCCs becomes larger) than when using SFs with intra-slot hopping.Consequently, the OCC multiplexing capacity (the maximum number of UEsto multiplex) can be increased.

Also, the UE does not perform frequency hopping when the UE isconfigured with PUCCH-starting-PRB and PUCCH-2nd-hop-PRB that aremutually equal, and it naturally follows that the UE does not performbase sequence hopping on a frequency-hop level either. Consequently, theUE uses one base sequence in one slot.

When the UE is configured with PUCCH-starting-PRB and PUCCH-2nd-hop-PRBthat are mutually different, as shown in FIG. 12B, the UE may use SFswith intra-slot hopping. In this case, the UE may use the first-hop SFbefore the frequency hopping timing, and use the second-hop SF after thefrequency hopping timing.

An SF with intra-slot hopping (each of the first-hop SF and thesecond-hop SF) is smaller than an SF without intra-slot hopping. Byusing SFs with intra-slot hopping, the OCC length becomes shorter thanwhen using an SF without intra-slot hopping. Consequently, when the UEmoves at high speed, the signal in a time-domain OCC varies less, andthe orthogonality of the time-domain OCC is less likely to deteriorate,so that the robustness against high-speed movement of the UE increases.

Also, the UE performs frequency hopping when the UE is configured withPUCCH-starting-PRB and PUCCH-2nd-hop-PRB that are mutually different, sothat the UE performs base sequence hopping (switches the base sequence)for at least one of PUCCH formats 0 to 4 at the timing of frequencyhopping. In this case, the UE may use base sequence #m₀ before thefrequency hopping timing, and use base sequence #m₁ after the frequencyhopping timing.

By changing the base sequence within a slot, a number of UEs are morelikely to use different base sequences, for example, at least eitherbefore or after frequency hopping (base sequence hopping). Therefore,the possibility that base sequences collide with each other decreases,and the robustness to inter-cell interference increases.

When the UE is configured with PUCCH-starting-PRB and PUCCH-2nd-hop-PRBthat are mutually different, the UE may assume thatPUCCH-frequency-hopping is not configured disabled (that is, configuredenabled). Also, when the UE is configured with PUCCH-starting-PRB andPUCCH-2nd-hop-PRB that are mutually different, the UE may use SFs withintra-slot hopping, regardless of whether PUCCH-frequency-hopping isenabled or disabled.

The UE may carry out UE operations so that the UE uses an SF withoutintra-slot hopping when PUCCH-frequency-hopping is configured disabledand PUCCH-starting-PRB and PUCCH-2nd-hop-PRB that are mutually equal areconfigured, and the UE uses SFs with intra-slot hopping whenPUCCH-frequency-hopping is configured enabled and PUCCH-starting-PRB andPUCCH-2nd-hop-PRB that are mutually different are configured. WhenPUCCH-frequency-hopping is configured disabled and PUCCH-starting-PRBand PUCCH-2nd-hop-PRB that are mutually different are configured, the UEto carry out the above UE operations may assume that this configurationis not valid (the UE may assume that this combination is not to beconfigured). When PUCCH-frequency-hopping is configured enabled andPUCCH-starting-PRB and PUCCH-2nd-hop-PRB that are mutually equal areconfigured, the UE to carry out the above UE operations may assume thatthis configuration is not valid (the UE may assume that this combinationis not to be configured).

According to the seventh example, the NW can change the SF, flexibly,based on the configuration of frequency hopping. Also, the UE canproperly control base sequence hopping based on the configuration offrequency hopping.

Also, since it is preferable to use the same base sequence within onetime-domain OCC, base sequence hopping on a slot level or afrequency-hop level is applied. Meanwhile, changing the cyclic shiftwithin one time-domain OCC has no impact on the orthogonality oftime-domain OCCs, so that hopping in units of symbols (or on a symbollevel) may be applied to the cyclic shift, or hopping on a slot level orcyclic shift hopping on a frequency-hop level may be applied, as withbase sequences.

Eighth Example

With an eighth example of the present invention, a method, by which UEdetermines the SF for PUCCH format 1 when the UE is configured withPUCCH-frequency-hopping (or an equivalent parameter), will be described.

SFs for PUCCH format 1 are associated with PUCCH lengths, SFs withoutintra-slot hopping and SFs with intra-slot hopping are associated withPUCCH lengths, and SFs with intra-slot hopping include first-hop SFs andsecond-hop SFs (see, for example, FIG. 2). Also, time-domain OCCsequences are associated with SFs (see, for example, FIG. 3).

Note that the UE may use SFs with intra-slot hopping even if the UE doesnot actually perform intra-slot frequency hopping for PUCCH.

The UE may determine the SF based on PUCCH-frequency-hopping, among thePUCCH resources that are configured.

When PUCCH-frequency-hopping is disabled, as shown in FIG. 13A, the UEmay use an SF without intra-slot hopping.

An SF without intra-slot hopping is greater than an SF with intra-slothopping (each of the first-hop SF and the second-hop SF). By using SFswithout intra-slot hopping, the OCC length becomes longer (the number ofOCCs becomes larger) than when using SFs with intra-slot hopping.Consequently, the OCC multiplexing capacity (the maximum number of UEsto multiplex) can be increased.

When PUCCH-frequency-hopping to indicate disablement is reported viahigher layer signaling, the UE may perform one of the followingoperations 1 and 2.

Operation 1

The UE assumes that the value of PUCCH-starting-PRB reported via higherlayer signaling and the value of PUCCH-2nd-hop-PRB reported via higherlayer signaling are the same.

Operation 2

The UE assumes that PUCCH-starting-PRB is reported via higher layersignaling, and ignores the value of PUCCH-2nd-hop-PRB, or assumes thatthe value of PUCCH-2nd-hop-PRB is not valid.

When PUCCH-frequency-hopping is enabled, as shown in FIG. 13B, the UEmay use SFs with intra-slot hopping. In this case, the UE may use thefirst-hop SF before the frequency hopping timing, and use the second-hopSF after the frequency hopping timing. Here, as for the timing forfrequency hopping, which has been described above, the number of symbolsof the first hop (the period before the frequency hopping timing in theslot) may be floor(the number of PUCCH symbols/2), and the number ofsymbols of the second hop (the period after the frequency hopping timingin the slot) may be ceil(the number of PUCCH symbols/2).

An SF with intra-slot hopping (each of the first-hop SF and thesecond-hop SF) is smaller than an SF without intra-slot hopping. Byusing SFs with intra-slot hopping, the OCC length becomes shorter thanwhen using an SF without intra-slot hopping. Consequently, when the UEmoves at high speed, the signal in a time-domain OCC varies less, andthe orthogonality of the time-domain OCC is less likely to deteriorate,so that the robustness against high-speed movement of the UE increases.

When PUCCH-frequency-hopping to indicate enablement is reported viahigher layer signaling, the UE may apply SFs with intra-slot hopping, tothe PUCCH, regardless of whether or not PUCCH-2nd-hop-PRB reported viahigher layer signaling is the same as PUCCH-starting-PRB reported viahigher layer signaling.

According to the eighth example, the NW (network, including, forexample, a radio base station, a gNB, etc.) can flexibly change the SF(the OCC length or the OCC multiplexing capacity) based on theconfiguration of frequency hopping.

Ninth Example

With a ninth example of the present invention, a method, by which UEdetermines the DMRS configurations for PUCCH format 3 and/or 4 when theUE is configured with PUCCH-frequency-hopping (or an equivalentparameter), will be described. The DMRS configuration may be thelocations (for example, the symbols) of the DMRS.

Similar to the case of SFs, for the DMRS configurations for PUCCH format3 and/or 4, DMRS configurations without intra-slot hopping (that is,with no intra-slot hopping) and DMRS configurations with intra-slothopping may be defined in the specification. A DMRS configuration withintra-slot hopping may include a DMRS configuration for the first hopand a DMRS configuration for the second hop.

The UE may determine the DMRS configuration based onPUCCH-frequency-hopping, among the PUCCH resources configured.

When PUCCH-frequency-hopping is disabled, as shown in FIG. 14A, the UEmay use a DMRS configuration without intra-slot hopping.

When PUCCH-frequency-hopping to indicate disablement is reported viahigher layer signaling, the UE may perform one of the followingoperations 1 and 2.

Operation 1

The UE assumes that the value of PUCCH-starting-PRB reported via higherlayer signaling and the value of PUCCH-2nd-hop-PRB reported via higherlayer signaling are the same.

Operation 2

The UE assumes that PUCCH-starting-PRB is reported via higher layersignaling, and ignores the value of PUCCH-2nd-hop-PRB, or assumes thatthe value of PUCCH-2nd-hop-PRB is not valid.

When PUCCH-frequency-hopping is enabled, as shown in FIG. 14B, the UEmay use a DMRS configuration with intra-slot hopping. In this case, theUE may use the first-hop DMRS configuration before the frequency hoppingtiming, and use the second-hop DMRS configuration after the frequencyhopping timing. Here, as for the timing for frequency hopping, which hasbeen described above, the number of symbols of the first hop (the periodbefore the frequency hopping timing in the slot) may be floor(the numberof PUCCH symbols/2), and the number of symbols of the second hop (theperiod after the frequency hopping timing in the slot) may be ceil(thenumber of PUCCH symbols/2).

When PUCCH-frequency-hopping to indicate enablement is reported viahigher layer signaling, the UE may use a DMRS configuration withintra-slot hopping, regardless of whether or not PUCCH-2nd-hop-PRBreported via higher layer signaling is the same as PUCCH-starting-PRBreported via higher layer signaling.

Note that the locations of the DMRS where frequency hopping is notapplied may be the same as the locations of the DMRS where frequencyhopping is applied.

According to the ninth example, the NW can flexibly change the DMRSconfiguration based on the configuration of frequency hopping.

Tenth Example

With a tenth example of the present invention, a method, by which UEdetermines the base sequence for at least one of PUCCH formats 0 to 4(in particular, PUCCH formats 0, 1, 3, and 4) and/or the SF for PUCCHformat 1, when the UE is configured with PUCCH-frequency-hopping (or anequivalent parameter), will be described. The base sequence may berepresented by a base sequence index.

The base sequence may be a CAZAC (Constant Amplitude ZeroAuto-Correlation) sequence such as a Zadoff-Chu sequence (for example, alow-PAPR (Peak-to-Average Power Ratio) sequence), may be a sequencedefined in the specification (for example, a low-PAPR sequence), or maybe a pseudo spreading sequence (for example, a Gold sequence). Forexample, a PUCCH having a bandwidth of one PRB may use one of a givennumber of sequences (where the given number may be, for example, 30, 60or a given value that is determined from the length of the basesequence) defined in the specification, as a base sequence. The basesequence may be used for UCI, or may be used for the DMRS.

Similar to the eighth example, for SFs for PUCCH format 1, SFs withoutintra-slot hopping and SFs with intra-slot hopping may be configured inadvance, or may be defined in the specification.

The UE may determine the base sequence and/or the SF based onPUCCH-frequency-hopping, among the PUCCH resources configured.

As base sequence hopping, a method of hopping the base sequence per slot(on a slot level) and a method of hopping the base sequence at thetiming of frequency hopping (per OCC length) (on a frequency-hop level,a time-domain-OCC level, etc.) may be possible.

Example 10-1

A case will be described here, in which base sequence hopping on a slotlevel is applied.

When PUCCH-frequency-hopping is disabled, as shown in FIG. 15A, the UEmay use an SF without intra-slot hopping.

An SF without intra-slot hopping is greater than an SF with intra-slothopping (each of the first-hop SF and the second-hop SF). By using SFswithout intra-slot hopping, the OCC length becomes longer (the number ofOCCs becomes larger) than when using SFs with intra-slot hopping.Consequently, the OCC multiplexing capacity (the maximum number of UEsto multiplex) can be increased.

When PUCCH-frequency-hopping to indicate disablement is reported viahigher layer signaling, the UE may perform one of the followingoperations 1 and 2.

Operation 1

The UE assumes that the value of PUCCH-starting-PRB reported via higherlayer signaling and the value of PUCCH-2nd-hop-PRB reported via higherlayer signaling are the same.

Operation 2

The UE assumes that PUCCH-starting-PRB is reported via higher layersignaling, and ignores the value of PUCCH-2nd-hop-PRB, or assumes thatthe value of PUCCH-2nd-hop-PRB is not valid.

When PUCCH-frequency-hopping is enabled, as shown in FIG. 15B, the UEmay use SFs with intra-slot hopping. In this case, the UE may use thefirst-hop SF before the frequency hopping timing, and use the second-hopSF after the frequency hopping timing. Here, as for the timing forfrequency hopping, which has been described above, the number of symbolsof the first hop (the period before the frequency hopping timing in theslot) may be floor(the number of PUCCH symbols/2), and the number ofsymbols of the second hop (the period after the frequency hopping timingin the slot) may be ceil(the number of PUCCH symbols/2).

An SF with intra-slot hopping (each of the first-hop SF and thesecond-hop SF) is smaller than an SF without intra-slot hopping. Byusing SFs with intra-slot hopping, the OCC length becomes shorter thanwhen using an SF without intra-slot hopping. Consequently, when the UEmoves at high speed, the signal in a time-domain OCC varies less, andthe orthogonality of the time-domain OCC is less likely to deteriorate,so that the robustness against high-speed movement of the UE increases.

Also, regardless of whether PUCCH-frequency-hopping is enabled ordisabled, the UE uses one base sequence #m₀ in one slot. In other words,the base sequence does not change before and after the frequency hoppingtiming.

When PUCCH-frequency-hopping to indicate enablement is reported viahigher layer signaling, the UE may apply SFs with intra-slot hopping, tothe PUCCH, regardless of whether or not PUCCH-2nd-hop-PRB reported viahigher layer signaling is the same as PUCCH-starting-PRB reported viahigher layer signaling.

According to this example, the NW can change the SF (OCC length),flexibly, depending on whether PUCCH-frequency-hopping is enabled ordisabled.

Example 10-2

A case will be described here, in which base sequence hopping on afrequency-hop level is applied.

Note that even if UE does not actually perform frequency hopping for thePUCCH, the UE may perform base sequence hopping at the timing offrequency hopping.

When PUCCH-frequency-hopping is disabled, as shown in FIG. 16A, the UEmay use an SF without intra-slot hopping.

An SF without intra-slot hopping is greater than an SF with intra-slothopping (each of the first-hop SF and the second-hop SF). By using SFswithout intra-slot hopping, the OCC length becomes longer (the number ofOCCs becomes larger) than when using SFs with intra-slot hopping.Consequently, the OCC multiplexing capacity (the maximum number of UEsto multiplex) can be increased.

When PUCCH-frequency-hopping to indicate disablement is reported viahigher layer signaling, the UE may perform one of the followingoperations 1 and 2.

Operation 1

The UE assumes that the value of PUCCH-starting-PRB reported via higherlayer signaling and the value of PUCCH-2nd-hop-PRB reported via higherlayer signaling are the same.

Operation 2

The UE assumes that PUCCH-starting-PRB is reported via higher layersignaling, and ignores the value of PUCCH-2nd-hop-PRB, or assumes thatthe value of PUCCH-2nd-hop-PRB is not valid.

Also, the UE does not perform frequency hopping whenPUCCH-frequency-hopping is disabled, and it naturally follows that theUE does not perform base sequence hopping on a frequency-hop leveleither. Consequently, the UE uses one base sequence #m₀ in one slot.

When PUCCH-frequency-hopping is enabled, as shown in FIG. 16B, the UEmay use SFs with intra-slot hopping. In this case, the UE may use thefirst-hop SF before the frequency hopping timing, and use the second-hopSF after the frequency hopping timing.

An SF with intra-slot hopping (each of the first-hop SF and thesecond-hop SF) is smaller than an SF without intra-slot hopping. Byusing SFs with intra-slot hopping, the OCC length becomes shorter thanwhen using an SF without intra-slot hopping. Consequently, when the UEmoves at high speed, the signal in a time-domain OCC varies less, andthe orthogonality of the time-domain OCC is less likely to deteriorate,so that the robustness against high-speed movement of the UE increases.

When PUCCH-frequency-hopping to indicate enablement is reported viahigher layer signaling, the UE may apply SFs with intra-slot hopping, tothe PUCCH, regardless of whether or not PUCCH-2nd-hop-PRB reported viahigher layer signaling is the same as PUCCH-starting-PRB reported viahigher layer signaling.

Also, if PUCCH-frequency-hopping is enabled, the UE performs frequencyhopping, and therefore, the UE performs base sequence hopping (switchesthe base sequence), at the timing of frequency hopping, for at least oneof PUCCH formats 0 to 4. In this case, the UE may use base sequence #m₀before the frequency hopping timing, and use base sequence #m₁ after thefrequency hopping timing.

By changing the base sequence within a slot, a number of UEs are morelikely to use different base sequences, for example, at least eitherbefore or after frequency hopping (base sequence hopping). Therefore,the possibility that base sequences collide with each other decreases,and the robustness to inter-cell interference increases.

When PUCCH-frequency-hopping to indicate enablement is reported viahigher layer signaling, the UE may apply SFs with intra-slot hopping, tothe PUCCH, regardless of whether or not PUCCH-2nd-hop-PRB reported viahigher layer signaling is the same as PUCCH-starting-PRB reported viahigher layer signaling.

According to the tenth example, the NW can change the SF, flexibly,based on the configuration of frequency hopping. Also, the UE canproperly control base sequence hopping based on the configuration offrequency hopping.

Also, since it is preferable to use the same base sequence within onetime-domain OCC, base sequence hopping on a slot level or afrequency-hop level is applied. Meanwhile, changing the cyclic shiftwithin one time-domain OCC has no impact on the orthogonality oftime-domain OCCs, so that hopping in units of symbols (or on a symbollevel) may be applied to the cyclic shift, or hopping on a slot level orcyclic shift hopping on a frequency-hop level may be applied, as withbase sequences.

(Radio Communication System)

Now, the structure of a radio communication system according to oneembodiment of the present invention will be described below. In thisradio communication system, communication is performed using 1 of theradio communication methods according to the herein-containedembodiments of the present invention, or a combination of these.

FIG. 17 is a diagram to show an exemplary schematic structure of a radiocommunication system according to one embodiment of the presentinvention. A radio communication system 1 can adopt carrier aggregation(CA) and/or dual connectivity (DC) to group a number of fundamentalfrequency blocks (component carriers) into one, where the LTE systembandwidth (for example, 20 MHz) constitutes one unit.

Note that the radio communication system 1 may be referred to as “LTE(Long-term evolution),” “LTE-A (LTE-Advanced),” “LTE-B (LTE-Beyond),”“SUPER 3G,” “IMT-Advanced,” “4G (4th generation mobile communicationsystem),” “5G (5th generation mobile communication system),” “NR (NewRadio),” “FRA (Future Radio Access),” “New-RAT (Radio AccessTechnology),” and so on, or may be seen as a system to implement these.

The radio communication system 1 includes a radio base station 11 thatforms a macro cell C1, with a relatively wide coverage, and radio basestations 12 (12 a to 12 c) that are placed within the macro cell C1 andthat form small cells C2, which are narrower than the macro cell C1.Also, user terminals 20 are placed in the macro cell C1 and in eachsmall cell C2. The arrangement and the number of cells and userterminals 20 and so forth are not limited to those illustrated in thedrawings.

The user terminals 20 can connect with both the radio base station 11and the radio base stations 12. The user terminals 20 are expected touse the macro cell C1 and the small cells C2 at the same time by meansof CA or DC. Furthermore, the user terminals 20 may apply CA or DC usinga number of cells (CCs) (for example, five or fewer CCs or six or moreCCs).

Between the user terminals 20 and the radio base station 11,communication can be carried out using a carrier of a relatively lowfrequency band (for example, 2 GHz) and a narrow bandwidth (referred toas, for example, an “existing carrier,” a “legacy carrier” and so on).Meanwhile, between the user terminals 20 and the radio base stations 12,a carrier of a relatively high frequency band (for example, 3.5 GHz, 5GHz and so on) and a wide bandwidth may be used, or the same carrier asthat used in the radio base station 11 may be used. Note that thestructure of the frequency band for use in each radio base station is byno means limited to these.

The radio base station 11 and a radio base station 12 (or two radio basestations 12) may be connected with each other by cables (for example, byoptical fiber in compliance with the CPRI (Common Public RadioInterface), the X2 interface, and so on), or by radio.

The radio base station 11 and the radio base stations 12 are eachconnected with higher station apparatus 30, and are connected with acore network 40 via the higher station apparatus 30. Note that thehigher station apparatus 30 may be, for example, access gatewayapparatus, a radio network controller (RNC), a mobility managemententity (MME) and so on, but these are by no means limiting. Also, eachradio base station 12 may be connected with the higher station apparatus30 via the radio base station 11.

Note that the radio base station 11 is a radio base station having arelatively wide coverage, and may be referred to as a “macro basestation,” a “central node,” an “eNB (eNodeB),” a “transmitting/receivingpoint” and so on. Also, the radio base stations 12 are radio basestations each having a local coverage, and may be referred to as “smallbase stations,” “micro base stations,” “pico base stations,” “femto basestations,” “HeNBs (Home eNodeBs),” “RRHs (Remote Radio Heads),”“transmitting/receiving points” and so on. Hereinafter, the radio basestations 11 and 12 will be collectively referred to as “radio basestations 10,” unless specified otherwise.

The user terminals 20 are terminals that support various communicationschemes such as LTE, LTE-A and so on, and may be either mobilecommunication terminals (mobile stations) or stationary communicationterminals (fixed stations).

In the radio communication system 1, as radio access schemes, orthogonalfrequency division multiple access (OFDMA) is applied to the downlink,and single-carrier frequency division multiple access (SC-FDMA) and/orOFDMA are applied to the uplink.

OFDMA is a multi-carrier communication scheme to perform communicationby dividing a frequency bandwidth into a number of narrow frequencybandwidths (subcarriers) and mapping data to each subcarrier. SC-FDMA isa single-carrier communication scheme to mitigate interference betweenterminals by dividing the system bandwidth into bands that are eachformed with one or contiguous resource blocks, per terminal, andallowing a number of terminals to use mutually different bands. Notethat the uplink and downlink radio access schemes are not limited to thecombinations of these, and other radio access schemes may be used aswell.

In the radio communication system 1, a downlink shared channel (PDSCH(Physical Downlink Shared CHannel)), which is used by each user terminal20 on a shared basis, a broadcast channel (PBCH (Physical BroadcastCHannel)), downlink L1/L2 control channels and so on are used asdownlink channels. User data, higher layer control information, SIBs(System Information Blocks) and so on are communicated in the PDSCH.Also, the MIB (Master Information Blocks) is communicated in the PBCH.

The downlink L1/L2 control channels include a PDCCH (Physical DownlinkControl CHannel), an EPDCCH (Enhanced Physical Downlink ControlCHannel), a PCFICH (Physical Control Format Indicator CHannel), a PHICH(Physical Hybrid-ARQ Indicator CHannel) and so on. Downlink controlinformation (DCI), which includes PDSCH and/or PUSCH schedulinginformation, is communicated by the PDCCH.

Note that scheduling information may be reported in DCI. For example,the DCI to schedule receipt of DL data may be referred to as “DLassignment,” and the DCI to schedule transmission of UL data may also bereferred to as “UL grant.”

The number of OFDM symbols to use for the PDCCH is communicated by thePCFICH. HARQ (Hybrid Automatic Repeat reQuest) delivery acknowledgmentinformation (also referred to as, for example, “retransmission controlinformation,” “HARQ-ACKs,” “ACKs/NACKs,” etc.) in response to the PUSCHis transmitted by the PHICH. The EPDCCH isfrequency-division-multiplexed with the PDSCH (downlink shared datachannel) and used to communicate DCI and so on, like the PDCCH.

In the radio communication system 1, an uplink shared channel (PUSCH(Physical Uplink Shared CHannel)), which is used by each user terminal20 on a shared basis, an uplink control channel (PUCCH (Physical UplinkControl CHannel)), a random access channel (PRACH (Physical RandomAccess CHannel)) and so on are used as uplink channels. User data,higher layer control information and so on are communicated by thePUSCH. Also, in the PUCCH, downlink radio quality information (CQI(Channel Quality Indicator)), delivery acknowledgment information,scheduling requests (SRs) and so on are communicated. By means of thePRACH, random access preambles for establishing connections with cellsare communicated.

In the radio communication system 1, cell-specific reference signals(CRSs), channel state information reference signals (CSI-RSs),demodulation reference signals (DMRSs), positioning reference signals(PRSs) and so on are communicated as downlink reference signals. Also,in the radio communication system 1, measurement reference signals (SRSs(Sounding Reference Signals)), demodulation reference signals (DMRSs)and so on are communicated as uplink reference signals. Note that theDMRSs may be referred to as “user terminal-specific reference signals(UE-specific reference signals).” Also, the reference signals to becommunicated are by no means limited to these.

<Radio Base Station>

FIG. 18 is a diagram to show an exemplary overall structure of a radiobase station according to one embodiment of the present invention. Aradio base station 10 has a number of transmitting/receiving antennas101, amplifying sections 102, transmitting/receiving sections 103, abaseband signal processing section 104, a call processing section 105and a communication path interface 106. Note that one or moretransmitting/receiving antennas 101, amplifying sections 102 andtransmitting/receiving sections 103 may be provided.

User data to be transmitted from the radio base station 10 to a userterminal 20 on the downlink is input from the higher station apparatus30, to the baseband signal processing section 104, via the communicationpath interface 106.

In the baseband signal processing section 104, the user data issubjected to transmission processes, including a PDCP (Packet DataConvergence Protocol) layer process, user data division and coupling,RLC (Radio Link Control) layer transmission processes such as RLCretransmission control, MAC (Medium Access Control) retransmissioncontrol (for example, an HARQ (Hybrid Automatic Repeat reQuest)transmission process), scheduling, transport format selection, channelcoding, an inverse fast Fourier transform (IFFT) process and a precodingprocess, and the result is forwarded to each transmitting/receivingsection 103. Furthermore, downlink control signals are also subjected totransmission processes such as channel coding and an inverse fastFourier transform, and forwarded to each transmitting/receiving section103.

Baseband signals that are precoded and output from the baseband signalprocessing section 104 on a per antenna basis are converted into a radiofrequency band in the transmitting/receiving sections 103, and thentransmitted. The radio frequency signals having been subjected tofrequency conversion in the transmitting/receiving sections 103 areamplified in the amplifying sections 102, and transmitted from thetransmitting/receiving antennas 101. The transmitting/receiving sections103 can be constituted by transmitters/receivers, transmitting/receivingcircuits or transmitting/receiving apparatus that can be described basedon general understanding of the technical field to which the presentinvention pertains. Note that a transmitting/receiving section 103 maybe structured as a transmitting/receiving section in one entity, or maybe constituted by a transmitting section and a receiving section.

Meanwhile, as for uplink signals, radio frequency signals that arereceived in the transmitting/receiving antennas 101 are each amplifiedin the amplifying sections 102. The transmitting/receiving sections 103receive the uplink signals amplified in the amplifying sections 102. Thereceived signals are converted into the baseband signal throughfrequency conversion in the transmitting/receiving sections 103 andoutput to the baseband signal processing section 104.

In the baseband signal processing section 104, user data that isincluded in the uplink signals that are input is subjected to a fastFourier transform (FFT) process, an inverse discrete Fourier transform(IDFT) process, error correction decoding, a MAC retransmission controlreceiving process, and RLC layer and PDCP layer receiving processes, andforwarded to the higher station apparatus 30 via the communication pathinterface 106. The call processing section 105 performs call processing(such as setting up and releasing communication channels), manages thestate of the radio base station 10, and manages the radio resources.

The communication path interface section 106 transmits and receivessignals to and from the higher station apparatus 30 via a giveninterface. Also, the communication path interface 106 may transmit andreceive signals (backhaul signaling) with other radio base stations 10via an inter-base station interface (which is, for example, opticalfiber that is in compliance with the CPRI (Common Public RadioInterface), the X2 interface, etc.).

Also, the transmitting/receiving sections 103 may transmit firstfrequency resource information (for example, PUCCH-starting-PRB), whichindicates the first frequency resource at the start of an uplink controlchannel (PUCCH), and second frequency resource information (for example,PUCCH-2nd-hop-PRB), which indicates a second frequency resource afterthe frequency hopping timing of the uplink control channel, to the userterminal 20. Furthermore, the transmitting/receiving sections 103 maytransmit frequency hopping information (PUCCH-frequency-hopping), whichindicates whether frequency hopping is enabled or not, to the userterminal 20.

FIG. 19 is a diagram to show an exemplary functional structure of aradio base station according to one embodiment of the present invention.Note that, although this example primarily shows functional blocks thatpertain to characteristic parts of the present embodiment, the radiobase station 10 has other functional blocks that are necessary for radiocommunication as well.

The baseband signal processing section 104 at least has a controlsection (scheduler) 301, a transmission signal generation section 302, amapping section 303, a received signal processing section 304 and ameasurement section 305. Note that these configurations have only to beincluded in the radio base station 10, and some or all of theseconfigurations may not be included in the baseband signal processingsection 104.

The control section (scheduler) 301 controls the whole of the radio basestation 10. The control section 301 can be constituted by a controller,a control circuit or control apparatus that can be described based ongeneral understanding of the technical field to which the presentinvention pertains.

The control section 301 controls, for example, the generation of signalsin the transmission signal generation section 302, the allocation ofsignals in the mapping section 303, and so on. Furthermore, the controlsection 301 controls the signal receiving processes in the receivedsignal processing section 304, the measurements of signals in themeasurement section 305, and so on.

The control section 301 controls the scheduling (for example, resourceallocation) of system information, downlink data signals (for example,signals transmitted in the PDSCH) and downlink control signals (forexample, signals transmitted in the PDCCH and/or the EPDCCH, such asdelivery acknowledgment information). Also, the control section 301controls the generation of downlink control signals, downlink datasignals, and so on based on the results of deciding whether or notretransmission control is necessary for uplink data signals, and so on.Also, the control section 301 controls the scheduling of synchronizationsignals (for example, PSS (Primary Synchronization Signal)/SSS(Secondary Synchronization Signal)), downlink reference signals (forexample, CRS, CSI-RS, DMRS, etc.) and so on.

Furthermore, the control section 301 controls the scheduling of uplinkdata signals (for example, signals transmitted in the PUSCH), uplinkcontrol signals (for example, signals transmitted in the PUCCH and/orthe PUSCH, such as delivery acknowledgment information), random accesspreambles (for example, signals transmitted in the PRACH), uplinkreference signals, and so forth.

Also, the control section 301 may control the receipt of an uplinkcontrol channel (PUCCH) based on first frequency resource informationand second frequency resource information. Furthermore, the controlsection 301 may control the receipt of an uplink control channel (PUCCH)based on first frequency resource information, second frequency resourceinformation, and frequency hopping information. Furthermore, the controlsection 301 may control the receipt of an uplink control channel (PUCCH)based on the frequency hopping information.

The transmission signal generation section 302 generates downlinksignals (downlink control signals, downlink data signals, downlinkreference signals, and so on) based on commands from the control section301, and outputs these signals to the mapping section 303. Thetransmission signal generation section 302 can be constituted by asignal generator, a signal generating circuit or signal generatingapparatus that can be described based on general understanding of thetechnical field to which the present invention pertains.

For example, the transmission signal generation section 302 generates DLassignments, which report downlink data allocation information, and/orUL grants, which report uplink data allocation information, based oncommands from the control section 301. DL assignments and UL grants areboth DCI, in compliance with DCI format. Also, downlink data signals aresubjected to the coding process, the modulation process and so on, byusing coding rates, modulation schemes and so forth that are determinedbased on, for example, channel state information (CSI) from each userterminal 20.

The mapping section 303 maps the downlink signals generated in thetransmission signal generation section 302 to given radio resourcesbased on commands from the control section 301, and outputs these to thetransmitting/receiving sections 103. The mapping section 303 can beconstituted by a mapper, a mapping circuit or mapping apparatus that canbe described based on general understanding of the technical field towhich the present invention pertains.

The received signal processing section 304 performs receiving processes(for example, demapping, demodulation, decoding and so on) of receivedsignals that are input from the transmitting/receiving sections 103.Here, the received signals include, for example, uplink signalstransmitted from the user terminal 20 (uplink control signals, uplinkdata signals, uplink reference signals, etc.). The received signalprocessing section 304 can be constituted by a signal processor, asignal processing circuit or signal processing apparatus that can bedescribed based on general understanding of the technical field to whichthe present invention pertains.

The received signal processing section 304 outputs the decodedinformation acquired through the receiving processes, to the controlsection 301. For example, when a PUCCH to contain an HARQ-ACK isreceived, the received signal processing section 304 outputs thisHARQ-ACK to the control section 301. Also, the received signalprocessing section 304 outputs the received signals and/or the signalsafter the receiving processes to the measurement section 305.

The measurement section 305 conducts measurements with respect to thereceived signals. The measurement section 305 can be constituted by ameasurer, a measurement circuit or measurement apparatus that can bedescribed based on general understanding of the technical field to whichthe present invention pertains.

For example, the measurement section 305 may perform RRM (Radio ResourceManagement) measurements, CSI (Channel State Information) measurements,and so on, based on the received signals. The measurement section 305may measure the received power (for example, RSRP (Reference SignalReceived Power)), the received quality (for example, RSRQ (ReferenceSignal Received Quality), SINR (Signal to Interference plus NoiseRatio), etc.), the signal strength (for example, RSSI (Received SignalStrength Indicator)), transmission path information (for example, CSI)and so on. The measurement results may be output to the control section301.

<User Terminal>

FIG. 20 is a diagram to show an exemplary overall structure of a userterminal according to one embodiment of the present invention. A userterminal 20 has a number of transmitting/receiving antennas 201,amplifying sections 202, transmitting/receiving sections 203, a basebandsignal processing section 204, and an application section 205. Note thatone or more transmitting/receiving antennas 201, amplifying sections 202and transmitting/receiving sections 203 may be provided.

Radio frequency signals that are received in the transmitting/receivingantennas 201 are amplified in the amplifying sections 202. Thetransmitting/receiving sections 203 receive the downlink signalsamplified in the amplifying sections 202. The received signals aresubjected to frequency conversion and converted into the baseband signalin the transmitting/receiving sections 203, and output to the basebandsignal processing section 204. A transmitting/receiving section 203 canbe constituted by a transmitters/receiver, a transmitting/receivingcircuit or transmitting/receiving apparatus that can be described basedon general understanding of the technical field to which the presentinvention pertains. Note that a transmitting/receiving section 203 maybe structured as a transmitting/receiving section in one entity, or maybe constituted by a transmitting section and a receiving section.

The baseband signal processing section 204 performs, for the basebandsignal that is input, an FFT process, error correction decoding, aretransmission control receiving process, and so on. Downlink user datais forwarded to the application section 205. The application section 205performs processes related to higher layers above the physical layer andthe MAC layer, and so on. Also, in the downlink data, the broadcastinformation can be also forwarded to the application section 205.

Meanwhile, uplink user data is input from the application section 205 tothe baseband signal processing section 204. The baseband signalprocessing section 204 performs a retransmission control transmissionprocess (for example, an HARQ transmission process), channel coding,precoding, a discrete Fourier transform (DFT) process, an IFFT processand so on, and the result is forwarded to the transmitting/receivingsections 203. Baseband signals that are output from the baseband signalprocessing section 204 are converted into a radio frequency band in thetransmitting/receiving sections 203, and transmitted. The radiofrequency signals that are subjected to frequency conversion in thetransmitting/receiving sections 203 are amplified in the amplifyingsections 202, and transmitted from the transmitting/receiving antennas201.

Also, the transmitting/receiving sections 203 may receive firstfrequency resource information (for example, PUCCH-starting-PRB), whichindicates the first frequency resource at the start of an uplink controlchannel, and second frequency resource information (for example,PUCCH-2nd-hop-PRB), which indicates a second frequency resource afterthe frequency hopping timing of the uplink control channel. Furthermore,the transmitting/receiving sections 203 may receive frequency hoppinginformation (PUCCH-frequency-hopping), which indicates whether frequencyhopping is enabled or not.

FIG. 21 is a diagram to show an exemplary functional structure of a userterminal according to one embodiment of the present invention. Notethat, although this example primarily shows functional blocks thatpertain to characteristic parts of the present embodiment, the userterminal 20 has other functional blocks that are necessary for radiocommunication as well.

The baseband signal processing section 204 provided in the user terminal20 at least has a control section 401, a transmission signal generationsection 402, a mapping section 403, a received signal processing section404, and a measurement section 405. Note that these configurations haveonly to be included in the user terminal 20, and some or all of theseconfigurations may not be included in the baseband signal processingsection 204.

The control section 401 controls the whole of the user terminal 20. Thecontrol section 401 can be constituted by a controller, a controlcircuit or control apparatus that can be described based on generalunderstanding of the technical field to which the present inventionpertains.

The control section 401 controls, for example, the generation of signalsin the transmission signal generation section 402, the allocation ofsignals in the mapping section 403, and so on. Furthermore, the controlsection 401 controls the signal receiving processes in the receivedsignal processing section 404, the measurements of signals in themeasurement section 405, and so on.

The control section 401 acquires the downlink control signals anddownlink data signals transmitted from the radio base station 10, viathe received signal processing section 404. The control section 401controls the generation of uplink control signals and/or uplink datasignals based on results of deciding whether or not retransmissioncontrol is necessary for the downlink control signals and/or downlinkdata signals, and so on.

The control section 401 may also control the transmission of an uplinkcontrol channel (PUCCH) based on whether or not a second frequencyresource, which is indicated in the second frequency resourceinformation (for example, PUCCH-2nd-hop-PRB), is the same as a firstfrequency resource, which is indicated in first frequency resourceinformation (for example, PUCCH-starting-PRB).

Also, based on whether or not the second frequency resource, which isindicated in the second frequency resource information, is the same asthe first frequency resource indicated in the first frequency resourceinformation, and based on frequency hopping information (for example,PUCCH-frequency-hopping), the control section 401 may determine at leastone of the spreading factor of the time-domain orthogonal cover codeapplied to the uplink control channel, the configuration of thedemodulation reference code included in the uplink control channel, andthe base sequence to apply to the uplink control channel (first to thirdexamples).

Furthermore, if the frequency hopping information indicates enablementand the second frequency resource indicated in the second frequencyresource information is different from the first frequency resourceindicated in the first frequency resource information, the controlsection 401 may change the base sequence at the timing of frequencyhopping (example 3-2 in the third example).

Furthermore, the control section 401 may judge whether or not to applyfrequency hopping, based on whether or not the second frequency resourceindicated in the second frequency resource information is the same asthe first frequency resource indicated in the first frequency resourceinformation (fourth example).

Also, based on whether or not the second frequency resource, which isindicated in the second frequency resource information, is the same asthe first frequency resource indicated in the first frequency resourceinformation, and the control section 401 may determine at least one ofthe spreading factor of the time-domain orthogonal cover code applied tothe uplink control channel, the configuration of the demodulationreference code included in the uplink control channel, and the basesequence to apply to the uplink control channel (fifth to seventhexamples).

Furthermore, the control section 401 may apply at least one of thespreading factor of the time-domain orthogonal cover code, theconfiguration of the demodulation reference code, and the base sequenceto the uplink control channel, based on the frequency hoppinginformation.

Also, for the time-domain orthogonal cover code applied to the uplinkcontrol channel, a first spreading factor for non-frequency hopping (forexample, an SF without intra-slot hopping (that is, with no intra-slothopping)) and a second spreading factor for frequency hopping (forexample, an SF with intra-slot hopping) are configured in advance, and,the control section 401 may apply the first spreading factor to theuplink control channel if the frequency hopping information indicatesdisablement, and apply the second spreading factor to the uplink controlchannel if the frequency hopping information indicates enablement.

Also, one spreading factor (for example, an SF without intra-slothopping (that is, with no intra-slot hopping)) and two spreading factors(for example, a first-hop SF and a second-hop SF in SFs with intra-slothopping) are configured in advance for the time-domain orthogonal covercode to apply to the uplink control channel, and the control section 401may apply one spreading factor to the uplink control channel when thefrequency hopping information indicates disablement, and apply twospreading factors before and after the timing of frequency hopping inthe uplink control channel, respectively, when frequency hoppinginformation indicates enablement.

Furthermore, the control section 401 may apply one base sequence to theuplink control channel, regardless of whether the frequency hoppinginformation is enabled or not.

Also, if the frequency hopping information indicates enablement, thecontrol section 401 may change the base sequence to apply to the uplinkcontrol channel at the timing of frequency hopping in the uplink controlchannel.

Also, a first demodulation reference signal configuration and a seconddemodulation reference signal configuration are configured in advancefor the demodulation reference code included in the uplink controlchannel, and the control section 401 may apply the first demodulationreference signal configuration to the uplink control channel when thefrequency hopping information indicates disablement, and apply thesecond demodulation reference signal configuration to the uplink controlchannel when the frequency hopping information indicates enablement.

The transmission signal generation section 402 generates uplink signals(uplink control signals, uplink data signals, uplink reference signals,etc.) based on commands from the control section 401, and outputs thesesignals to the mapping section 403. The transmission signal generationsection 402 can be constituted by a signal generator, a signalgenerating circuit, or signal generating apparatus that can be describedbased on general understanding of the technical field to which thepresent invention pertains.

For example, the transmission signal generation section 402 generatesuplink control signals such as delivery acknowledgement information,channel state information (CSI) and so on, based on commands from thecontrol section 401. Also, the transmission signal generation section402 generates uplink data signals based on commands from the controlsection 401. For example, when a UL grant is included in a downlinkcontrol signal that is reported from the radio base station 10, thecontrol section 401 commands the transmission signal generation section402 to generate an uplink data signal.

The mapping section 403 maps the uplink signals generated in thetransmission signal generation section 402 to radio resources based oncommands from the control section 401, and outputs these to thetransmitting/receiving sections 203. The mapping section 403 can beconstituted by a mapper, a mapping circuit or mapping apparatus that canbe described based on general understanding of the technical field towhich the present invention pertains.

The received signal processing section 404 performs receiving processes(for example, demapping, demodulation, decoding and so on) for receivedsignals that are input from the transmitting/receiving sections 203.Here, the received signals include, for example, downlink signals(downlink control signals, downlink data signals, downlink referencesignals, and so on) that are transmitted from the radio base station 10.The received signal processing section 404 can be constituted by asignal processor, a signal processing circuit or signal processingapparatus that can be described based on general understanding of thetechnical field to which the present invention pertains. Also, thereceived signal processing section 404 can constitute the receivingsection according to the present disclosure.

The received signal processing section 404 outputs the decodedinformation acquired through the receiving processes, to the controlsection 401. The received signal processing section 404 outputs, forexample, broadcast information, system information, RRC signaling, DCIand so on, to the control section 401. Also, the received signalprocessing section 404 outputs the received signals and/or the signalsafter the receiving processes to the measurement section 405.

The measurement section 405 conducts measurements with respect to thereceived signals. The measurement section 405 can be constituted by ameasurer, a measurement circuit or measurement apparatus that can bedescribed based on general understanding of the technical field to whichthe present invention pertains.

For example, the measurement section 405 may perform RRM measurements,CSI measurements, and so on, based on the received signals. Themeasurement section 405 may measure the received power (for example,RSRP), the received quality (for example, RSRQ, SINR, etc.), the signalstrength (for example, RSSI), transmission path information (forexample, CSI), and so on. The measurement results may be output to thecontrol section 401.

<Hardware Structure>

Note that the block diagrams that have been used to describe the aboveembodiment show blocks in functional units. These functional blocks(components) may be implemented in arbitrary combinations of hardwareand/or software. Also, the method for implementing each functional blockis not particularly limited. That is, each functional block may berealized by one piece of apparatus that is physically and/or logicallyaggregated, or may be realized by directly and/or indirectly connectingtwo or more physically and/or logically-separate pieces of apparatus (byusing cables and/or radio, for example) and using these multiple piecesof apparatus.

For example, the radio base station, user terminals and so on accordingto one embodiment of the present invention may function as a computerthat executes the processes of the radio communication method of thepresent invention. FIG. 22 is a diagram to show an exemplary hardwarestructure of a radio base station and a user terminal according to oneembodiment of the present invention. Physically, the above-describedradio base stations 10 and user terminals 20 may be formed as a computerapparatus that includes a processor 1001, a memory 1002, a storage 1003,communication apparatus 1004, input apparatus 1005, output apparatus1006, a bus 1007 and so on.

Note that, in the following description, the term “apparatus” may bereplaced by “circuit,” “device,” “unit” and so on. Note that, thehardware structure of a radio base station 10 and a user terminal 20 maybe designed to include one or more of each apparatus shown in thedrawings, or may be designed not to include part of the apparatus.

For example, although only one processor 1001 is shown, a number ofprocessors may be provided. Furthermore, processes may be implementedwith one processor, or processes may be implemented simultaneously or insequence, or by using different techniques, on one or more processors.Note that the processor 1001 may be implemented with one or more chips.

The functions of the radio base station 10 and the user terminal 20 areimplemented by, for example, allowing hardware such as the processor1001 and the memory 1002 to read given software (programs), and allowingthe processor 1001 to do calculations, control communication thatinvolves the communication apparatus 1004, control the reading and/orwriting of data in the memory 1002 and the storage 1003, and so on.

The processor 1001 may control the whole computer by, for example,running an operating system. The processor 1001 may be constituted by acentral processing unit (CPU), which includes interfaces with peripheralapparatus, control apparatus, computing apparatus, a register, and soon. For example, the above-described baseband signal processing section104 (204), call processing section 105, and so on may be implemented bythe processor 1001.

Furthermore, the processor 1001 reads programs (program codes), softwaremodules, data, and so forth from the storage 1003 and/or thecommunication apparatus 1004, into the memory 1002, and executes variousprocesses according to these. As for the programs, programs to allowcomputers to execute at least part of the operations of theabove-described embodiment may be used. For example, the control section401 of the user terminals 20 may be implemented by control programs thatare stored in the memory 1002 and that operate on the processor 1001,and other functional blocks may be implemented likewise.

The memory 1002 is a computer-readable recording medium, and may beconstituted by, for example, at least one of a ROM (Read Only Memory),an EPROM (Erasable Programmable ROM), an EEPROM (Electrically EPROM), aRAM (Random Access Memory), and other appropriate storage media. Thememory 1002 may be referred to as a “register,” a “cache,” a “mainmemory (primary storage apparatus),” and so on. The memory 1002 canstore executable programs (program codes), software modules and so onfor implementing the radio communication methods according toembodiments of the present invention.

The storage 1003 is a computer-readable recording medium, and may beconstituted by, for example, at least one of a flexible disk, a floppy(registered trademark) disk, a magneto-optical disk (for example, acompact disc (CD-ROM (Compact Disc ROM) or the like), a digitalversatile disc, a Blu-ray (registered trademark) disk, etc.), aremovable disk, a hard disk drive, a smart card, a flash memory device(for example, a card, a stick, a key drive, etc.), a magnetic stripe, adatabase, a server, and/or other appropriate storage media. The storage1003 may be referred to as “secondary storage apparatus.”

The communication apparatus 1004 is hardware (transmitting/receivingdevice) for allowing inter-computer communication by using cable and/orwireless networks, and may be referred to as, for example, a “networkdevice,” a “network controller,” a “network card,” a “communicationmodule,” and so on. The communication apparatus 1004 may be configuredto include a high frequency switch, a duplexer, a filter, a frequencysynthesizer and so on, in order to implement, for example, frequencydivision duplex (FDD) and/or time division duplex (TDD). For example,the above-described transmitting/receiving antennas 101 (201),amplifying sections 102 (202), transmitting/receiving sections 103(203), communication path interface 106 and so on may be implemented bythe communication apparatus 1004.

The input apparatus 1005 is an input device for receiving input fromoutside (for example, a keyboard, a mouse, a microphone, a switch, abutton, a sensor and so on). The output apparatus 1006 is an outputdevice for allowing sending output to outside (for example, a display, aspeaker, an LED (Light Emitting Diode) lamp, and so on). Note that theinput apparatus 1005 and the output apparatus 1006 may be provided in anintegrated structure (for example, a touch panel).

Furthermore, these pieces of apparatus, including the processor 1001,the memory 1002 and so on, are connected by the bus 1007, so as tocommunicate information. The bus 1007 may be formed with a single bus,or may be formed with buses that vary between pieces of apparatus.

Also, the radio base station 10 and the user terminal 20 may bestructured to include hardware such as a microprocessor, a digitalsignal processor (DSP), an ASIC (Application-Specific IntegratedCircuit), a PLD (Programmable Logic Device), an FPGA (Field ProgrammableGate Array) and so on, and part or all of the functional blocks may beimplemented by these pieces of hardware. For example, the processor 1001may be implemented with at least one of these pieces of hardware.

(Variations)

Note that, the terminology used in this specification and theterminology that is needed to understand this specification may bereplaced by other terms that communicate the same or similar meanings.For example, a “channel” and/or a “symbol” may be replaced by a “signal”(or “signaling”). Also, a “signal” may be a “message.” A referencesignal may be abbreviated as an “RS,” and may be referred to as a“pilot,” a “pilot signal” and so on, depending on which standardapplies. Furthermore, a “component carrier (CC)” may be referred to as a“cell,” a “frequency carrier,” a “carrier frequency,” and so on.

Furthermore, a radio frame may be comprised of one or more periods(frames) in the time domain. One or more periods (frames) thatconstitute a radio frame may be each referred to as a “subframe.”Furthermore, a subframe may be comprised of one or multiple slots in thetime domain. A subframe may be a fixed time duration (for example, 1ms), which does not depend on numerology.

Furthermore, a slot may be comprised of one or more symbols in the timedomain (OFDM (Orthogonal Frequency Division Multiplexing) symbols,SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, andso on). Also, a slot may be a time unit based on numerology. Also, aslot may include a number of minislots. Each minislot may be comprisedof one or more symbols in the time domain. Also, a minislot may bereferred to as a “subslot.”

A radio frame, a subframe, a slot, a minislot, and a symbol all refer toa unit of time in signal communication. A radio frame, a subframe, aslot, a minislot and a symbol may be each called by other applicablenames. For example, one subframe may be referred to as a “transmissiontime interval (TTI),” or a number of contiguous subframes may bereferred to as a “TTI,” or one slot or one minislot may be referred toas a “TTI.” That is, a subframe and/or a TTI may be a subframe (1 ms) inexisting LTE, may be a shorter period than 1 ms (for example, one tothirteen symbols), or may be a longer period of time than 1 ms. Notethat the unit to represent a TTI may be referred to as a “slot,” a“minislot” and so on, instead of a “subframe.”

Here, a TTI refers to the minimum time unit for scheduling in radiocommunication, for example. For example, in LTE systems, a radio basestation schedules the radio resources (such as the frequency bandwidthand transmission power each user terminal can use) to allocate to eachuser terminal in TTI units. Note that the definition of TTIs is notlimited to this.

A TTI may be the transmission time unit of channel-encoded data packets(transport blocks), code blocks and/or codewords, or may be the unit ofprocessing in scheduling, link adaptation, and so on. Note that, when aTTI is given, the period of time (for example, the number of symbols) inwhich transport blocks, code blocks and/or codewords are actually mappedmay be shorter than the TTI.

Note that, when one slot or one minislot is referred to as a “TTI,” oneor more TTIs (that is, one or multiple slots or one or more minislots)may be the minimum time unit of scheduling. Also, the number of slots(the number of minislots) to constitute this minimum time unit forscheduling may be controlled.

A TTI having a time length of 1 ms may be referred to as a “normal TTI”(TTI in LTE Rel. 8 to 12), a “long TTI,” a “normal subframe,” a “longsubframe,” and so on. A TTI that is shorter than a normal TTI may bereferred to as a “shortened TTI,” a “short TTI,” a “partial TTI” (or a“fractional TTI”), a “shortened subframe,” a “short subframe,” a“minislot,” a “sub-slot,” and so on.

Note that a long TTI (for example, a normal TTI, a subframe, etc.) maybe replaced with a TTI having a time duration exceeding 1 ms, and ashort TTI (for example, a shortened TTI) may be replaced with a TTIhaving a TTI length less than the TTI length of a long TTI and not lessthan 1 ms.

A resource block (RB) is the unit of resource allocation in the timedomain and the frequency domain, and may include one or a number ofcontiguous subcarriers in the frequency domain. Also, an RB may includeone or more symbols in the time domain, and may be one slot, oneminislot, one subframe or one TTI in length. One TTI and one subframeeach may be comprised of one or more resource blocks. Note that one ormore RBs may be referred to as a “physical resource block (PRB (PhysicalRB)),” a “subcarrier group (SCG),” a “resource element group (REG),” a“PRB pair,” an “RB pair,” and so on.

Furthermore, a resource block may be comprised of one or more resourceelements (REs). For example, one RE may be a radio resource field of onesubcarrier and one symbol.

Note that the structures of radio frames, subframes, slots, minislots,symbols, and so on described above are simply examples. For example,configurations pertaining to the number of subframes included in a radioframe, the number of slots included in a subframe or a radio frame, thenumber of minislots included in a slot, the number of symbols and RBsincluded in a slot or a minislot, the number of subcarriers included inan RB, the number of symbols in a TTI, the symbol duration, the lengthof cyclic prefixes (CPs), and so on can be variously changed.

Also, the information and parameters described in this specification maybe represented in absolute values or in relative values with respect togiven values, or may be represented using other applicable information.For example, a radio resource may be specified by a given index.

The names used for parameters and so on in this specification are in norespect limiting. For example, since various channels (PUCCH (PhysicalUplink Control CHannel), PDCCH (Physical Downlink Control CHannel) andso on) and information elements can be identified by any suitable names,the various names assigned to these individual channels and informationelements are in no respect limiting.

The information, signals and/or others described in this specificationmay be represented by using a variety of different technologies. Forexample, data, instructions, commands, information, signals, bits,symbols and chips, all of which may be referenced throughout theherein-contained description, may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orphotons, or any combination of these.

Also, information, signals, and so on can be output from higher layersto lower layers, and/or from lower layers to higher layers. Information,signals, and so on may be input and/or output via a number of networknodes.

The information, signals, and so on that are input and/or output may bestored in a specific location (for example, in a memory), or may bemanaged in a control table. The information, signals, and so on to beinput and/or output can be overwritten, updated, or appended. Theinformation, signals, and so on that are output may be deleted. Theinformation, signals, and so on that are input may be transmitted toother pieces of apparatus.

The method of reporting information is by no means limited to those usedin the examples/embodiments described in this specification, and othermethods may be used as well. For example, reporting of information maybe implemented by using physical layer signaling (for example, downlinkcontrol information (DCI), uplink control information (UCI)), higherlayer signaling (for example, RRC (Radio Resource Control) signaling,broadcast information (the master information block (MIB), systeminformation blocks (SIBs) and so on), MAC (Medium Access Control)signaling, etc.), and other signals and/or combinations of these.

Note that physical layer signaling may be referred to as “L1/L2 (Layer1/Layer 2) control information (L1/L2 control signals),” “L1 controlinformation (L1 control signal),” and so on. Also, RRC signaling may bereferred to as “RRC messages,” and can be, for example, an “RRCconnection setup message,” “RRC connection reconfiguration message,” andso on. Also, MAC signaling may be reported using, for example, MACcontrol elements (MAC CEs (Control Elements)).

Also, reporting of given information (for example, reporting ofinformation to the effect that “X holds”) does not necessarily have tobe sent explicitly, and can be sent in an implicit way (for example, bynot reporting this piece of information, by reporting another piece ofinformation, and so on).

Decisions may be made in values represented by one bit (0 or 1), may bemade in Boolean values that represent true or false, or may be made bycomparing numerical values (for example, comparison against a givenvalue).

Software, whether referred to as “software,” “firmware,” “middleware,”“microcode,” or “hardware description language,” or called by othernames, should be interpreted broadly, to mean instructions, instructionsets, code, code segments, program codes, programs, subprograms,software modules, applications, software applications, softwarepackages, routines, subroutines, objects, executable files, executionthreads, procedures, functions, and so on.

Also, software, commands, information and so on may be transmitted andreceived via communication media. For example, when software istransmitted from a website, a server or other remote sources by usingwired technologies (coaxial cables, optical fiber cables, twisted-paircables, digital subscriber lines (DSL) and so on), and/or wirelesstechnologies (infrared radiation, microwaves, and so on), these wiredtechnologies and/or wireless technologies are also included in thedefinition of communication media.

The terms “system” and “network” as used herein are usedinterchangeably.

As used herein, the terms “base station (BS),” “radio base station,”“eNB,” “gNB,” “cell,” “sector,” “cell group,” “carrier,” and “componentcarrier” may be used interchangeably. A base station may be referred toas a “fixed station,” “NodeB,” “eNodeB (eNB),” “access point,”“transmission point,” “receiving point,” “femto cell,” “small cell,” andso on.

A base station can accommodate one or more (for example, three) cells(also referred to as “sectors”). When a base station accommodates anumber of cells, the entire coverage area of the base station can bepartitioned into multiple smaller areas, and each smaller area canprovide communication services through base station subsystems (forexample, indoor small base stations (RRHs (Remote Radio Heads))). Theterm “cell” or “sector” refers to part or all of the coverage area of abase station and/or a base station subsystem that provides communicationservices within this coverage.

As used herein, the terms “mobile station (MS),” “user terminal,” “userequipment (UE),” and “terminal” may be used interchangeably. A basestation may be referred to as a “fixed station,” “NodeB,” “eNodeB(eNB),” “access point,” “transmission point,” “receiving point,” “femtocell,” “small cell,” and so on.

A mobile station may be referred to, by a person skilled in the art, asa “subscriber station,” “mobile unit,” “subscriber unit,” “wirelessunit,” “remote unit,” “mobile device,” “wireless device,” “wirelesscommunication device,” “remote device,” “mobile subscriber station,”“access terminal,” “mobile terminal,” “wireless terminal,” “remoteterminal,” “handset,” “user agent,” “mobile client,” “client,” or someother suitable terms.

Furthermore, the radio base stations in this specification may beinterpreted as user terminals. For example, the examples/embodiments ofthe present disclosure may be applied to a configuration in whichcommunication between a radio base station and a user terminal isreplaced with communication among a number of user terminals (D2D(Device-to-Device)). In this case, user terminals 20 may have thefunctions of the radio base stations 10 described above. In addition,terms such as “uplink” and “downlink” may be interpreted as “side.” Forexample, an “uplink channel” may be interpreted as a “side channel.”

Likewise, the user terminals in this specification may be interpreted asradio base stations. In this case, the radio base stations 10 may havethe functions of the user terminals 20 described above.

Certain actions which have been described in this specification to beperformed by base stations may, in some cases, be performed by theirupper nodes. In a network comprised of one or more network nodes withbase stations, it is clear that various operations that are performed soas to communicate with terminals can be performed by base stations, oneor more network nodes (for example, MMEs (Mobility Management Entities),S-GWs (Serving-Gateways), and so on may be possible, but these are notlimiting) other than base stations, or combinations of these.

The examples/embodiments illustrated in this specification may be usedindividually or in combinations, which may be switched depending on themode of implementation. Also, the order of processes, sequences,flowcharts, and so on that have been used to describe theexamples/embodiments herein may be re-ordered as long as inconsistenciesdo not arise. For example, although various methods have beenillustrated in this specification with various components of steps inexemplary orders, the specific orders that are illustrated herein are byno means limiting.

The examples/embodiments illustrated in this specification may beapplied to systems that use LTE (Long Term Evolution), LTE-A(LTE-Advanced), LTE-B (LTE-Beyond), SUPER 3G, IMT-Advanced, 4G (4thgeneration mobile communication system), 5G (5th generation mobilecommunication system), FRA (Future Radio Access), New-RAT (Radio AccessTechnology), NR (New Radio), NX (New radio access), FX (Futuregeneration radio access), GSM (registered trademark) (Global System forMobile communications), CDMA 2000, UMB (Ultra Mobile Broadband), IEEE802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registeredtrademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registeredtrademark), other adequate radio communication methods, and/ornext-generation systems that are enhanced based on these.

The phrase “based on” as used in this specification does not mean “basedonly on” unless otherwise specified. In other words, the phrase “basedon” means both “based only on” and “based at least on.”

Reference to elements with designations such as “first,” “second,” andso on as used herein does not generally limit the number/quantity ororder of these elements. These designations are used herein only forconvenience, as a method for distinguishing between two or moreelements. In this way, reference to the first and second elements doesnot imply that only two elements may be employed, or that the firstelement must precede the second element in some way.

The terms “judge” and “determine” as used herein may encompass a widevariety of actions. For example, to “judge” and “determine” as usedherein may be interpreted to mean making judgements and determinationsrelated to calculating, computing, processing, deriving, investigating,looking up (for example, searching a table, a database, or some otherdata structure), ascertaining, and so on. Furthermore, to “judge” and“determine” as used herein may be interpreted to mean making judgementsand determinations related to receiving (for example, receivinginformation), transmitting (for example, transmitting information),inputting, outputting, accessing (for example, accessing data in amemory) and so on. In addition, to “judge” and “determine” as usedherein may be interpreted to mean making judgements and determinationsrelated to resolving, selecting, choosing, establishing, comparing, andso on. In other words, to “judge” and “determine” as used herein may beinterpreted to mean making judgements and determinations related to someaction.

As used herein, the terms “connected” and “coupled,” or any variation ofthese terms, mean all direct or indirect connections or coupling betweentwo or more elements, and may include the presence of one or moreintermediate elements between two elements that are “connected” or“coupled” to each other. The coupling or connection between the elementsmay be physical, logical, or a combination of these. For example,“connection” may be interpreted as “access.”

As used herein, when two elements are connected, these elements may beconsidered “connected” or “coupled” to each other by using one or moreelectrical wires, cables, and/or printed electrical connections, and, asa number of non-limiting and non-inclusive examples, by usingelectromagnetic energy having wavelengths of the radio frequency region,the microwave region and/or the optical region (both visible andinvisible).

In the present specification, the phrase “A and B are different” maymean “A and B are different from each other.” The terms such as “leave,”“coupled” and the like may be interpreted as well.

When terms such as “include,” “comprise” and variations of these areused in this specification or in claims, these terms are intended to beinclusive, in a manner similar to the way the term “provide” is used.Furthermore, the term “or” as used in this specification or in claims isintended to be not an exclusive disjunction.

Now, although the present invention has been described in detail above,it should be obvious to a person skilled in the art that the presentinvention is by no means limited to the embodiments described herein.The present invention can be implemented with various corrections and invarious modifications, without departing from the spirit and scope ofthe present invention defined by the recitations of claims.Consequently, the description herein is provided only for the purpose ofexplaining examples, and should by no means be construed to limit thepresent invention in any way.

The invention claimed is:
 1. A terminal comprising: a receiver thatreceives frequency hopping information, which indicates whetherfrequency hopping for an uplink control channel is enabled or not; and aprocessor that applies at least one of a spreading factor for atime-domain orthogonal cover code, a configuration of a demodulationreference code and a base sequence, to the uplink control channel, basedon the frequency hopping information, wherein: a first spreading factorfor non-frequency hopping and a second spreading factor for frequencyhopping are configured, in advance, for the time-domain orthogonal covercode to apply to the uplink control channel; and the processor appliesthe first spreading factor to the uplink control channel when thefrequency hopping information indicates disablement, and applies thesecond spreading factor to the uplink control channel when the frequencyhopping information indicates enablement.
 2. The terminal according toclaim 1, wherein the processor applies one base sequence to the uplinkcontrol channel regardless of whether the frequency hopping informationis enabled or not.
 3. The terminal according to claim 1, wherein, whenthe frequency hopping information indicates enablement, the processorchanges a base sequence to apply to the uplink control channel at atiming of the frequency hopping in the uplink control channel.
 4. Theterminal according to claim 1, wherein: a first demodulation referencesignal configuration and a second demodulation reference signalconfiguration are configured, in advance, for the demodulation referencecode included in the uplink control channel; and the processor appliesthe first demodulation reference signal configuration to the uplinkcontrol channel when the frequency hopping information indicatesdisablement, and applies the second demodulation reference signalconfiguration to the uplink control channel when the frequency hoppinginformation indicates enablement.
 5. A radio communication method for aterminal, comprising: receiving frequency hopping information, whichindicates whether frequency hopping for an uplink control channel isenabled or not; and applying at least one of a spreading factor for atime-domain orthogonal cover code, a configuration of a demodulationreference code and a base sequence, to the uplink control channel, basedon the frequency hopping information, wherein: a first spreading factorfor non-frequency hopping and a second spreading factor for frequencyhopping are configured, in advance, for the time-domain orthogonal covercode to apply to the uplink control channel; and the applying the firstspreading factor to the uplink control channel when the frequencyhopping information indicates disablement, and the applying the secondspreading factor to the uplink control channel when the frequencyhopping information indicates enablement.
 6. A system comprising aterminal and a base station, wherein the terminal comprises: a receiverthat receives frequency hopping information, which indicates whetherfrequency hopping for an uplink control channel is enabled or not; and aprocessor that applies at least one of a spreading factor for atime-domain orthogonal cover code, a configuration of a demodulationreference code and a base sequence, to the uplink control channel, basedon the frequency hopping information, and the base station comprises: atransmitter that transmits the frequency hopping information, wherein: afirst spreading factor for non-frequency hopping and a second spreadingfactor for frequency hopping are configured, in advance, for thetime-domain orthogonal cover code to apply to the uplink controlchannel; and the processor applies the first spreading factor to theuplink control channel when the frequency hopping information indicatesdisablement, and applies the second spreading factor to the uplinkcontrol channel when the frequency hopping information indicatesenablement.